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plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.

Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilage which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria and plant pests.

Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizer availability, attack by pests, and poor storage after harvesting

All of the following are examples of an adverse situation for crops EXCEPT________

A. pest aggression

B. inadequate water

C. insufficient fertilize

D. proper storage 

1
4 tháng 2 2018

Đáp án D
Suy ra từ câu cuối : such adverse situations as inadequate water supply, limited fertilizer availability, attack by pests, and poor storage after harvesting.

plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums...
Đọc tiếp

plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.

Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilage which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria and plant pests.

Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizer availability, attack by pests, and poor storage after harvesting

Which is one of the ways in which the epicuticular wax protects the plant?

A. It helps the plant to attack aggressors

B. It guards against bacteria

C. It releases gases against plant pests

D. It helps the plant to avoid excessive moisture intake

1
24 tháng 4 2018

Đáp án B
Đ2: It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria and plant pests. Nó (the epicuticular wax) cũng bảo vệ cây cối khỏi những tấn công bên ngoài, cái mà đến từ những tác
nhân vô cơ như là các loại khí, hoặc những tác nhân hữu cơ bao gồm vi khuẩn và côn trùng cây

plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums...
Đọc tiếp

plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.

Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilage which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria and plant pests.

Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizer availability, attack by pests, and poor storage after harvesting

Which of the following is a mechanical or physical mechanism that desert plants use?

A. The plant’s shape

B. The vast leaf size

C. The small root system

D. The high water system

1
16 tháng 11 2017

Đáp án A
Đ2: Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. (bao gồm: bóng cây, lá nhỏ, và bộ rễ lớn)

plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums...
Đọc tiếp

plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.

Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilage which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria and plant pests.

Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizer availability, attack by pests, and poor storage after harvesting

What is an example of an inorganic agent that may attack plants?

A. Pests

B. Gas

C. Bacteria

D. Insects

1
11 tháng 9 2019

Đáp án B
Đ2: which can come from inorganic agents such as gases, or organic agents which include bacteria and plant pests. -> gases

plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums...
Đọc tiếp

plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.

Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilage which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria and plant pests.

Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizer availability, attack by pests, and poor storage after harvesting

The word “arable” in the 1st paragraph is closest in meaning to ________

A. parched

B. barren

C. fertile

D. marsh

1
20 tháng 3 2017

Đáp án C
Arable : có thể trồng trọt được = fertile: màu mỡ Parched = barren: khô cằn Marsh: đầm lầy

plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums...
Đọc tiếp

plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.

Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilage which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria and plant pests.

Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizer availability, attack by pests, and poor storage after harvesting

It can be inferred that synthetic stimulate waxes________

A. have been determined to be impervious to organic and inorganic agents

B. have not succeeded

C. have not been developed yet

D. have the quality of causing bacteria

1
25 tháng 11 2017

Đáp án C
Đ3: Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed.
Chú ý cụm từ: If successfully developed : câu trên đang nói đến các nhà nghiên cứu nói về synthetic
waxes, câu dưới nói: nếu phát triển thành công -> nghĩa là vẫn chưa phát triển được

plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums...
Đọc tiếp

plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.

Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilage which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria and plant pests.

Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizer availability, attack by pests, and poor storage after harvesting

The word “aggression” in the 2nd paragraph is closest in meaning to_________

A. surroundings

B. conditions

C. attack

D. agitation

1
3 tháng 3 2019

Đáp án C
Aggression = attack : tấn công

plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums...
Đọc tiếp

plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.

Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilage which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria and plant pests.

Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizer availability, attack by pests, and poor storage after harvesting

The word “extensive” in the 2nd paragraph is closest in meaning to _________

A. spongy

B. widespread

C. comprehensive

D. shallowB


Extensive : rộng lớn = widespread
Spongy: rỗ, shallow: nông, comprehensive: nhanh hiểu, thông minh

1
25 tháng 8 2018

Đáp án B

Extensive : rộng lớn = widespread
Spongy: rỗ, shallow: nông, comprehensive: nhanh hiểu, thông minh

plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums...
Đọc tiếp

plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.

Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilage which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria and plant pests.

Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizer availability, attack by pests, and poor storage after harvesting

The word “It” in the 2nd paragraph refers to________

A. the epicuticular wax layer

B. the loss of internal moisture

C. an impervious plant like cover

D. another chemical mechanism

1
30 tháng 1 2018

Đáp án A
Như câu 49 => it là the epicuticular wax

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.Water scarcity is fast becoming one of the major limiting factors in world crop production. In many areas, poor agricultural practices have led to increasing desertification and the loss of formerly arable lands. Consequently, those plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.

Water scarcity is fast becoming one of the major limiting factors in world crop production. In many areas, poor agricultural practices have led to increasing desertification and the loss of formerly arable lands. Consequently, those plant species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.

Plants use several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilage which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria and plant pests.

Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizer availability, attack by pests, and poor storage after harvesting

This passage deals mainly with ________

A. decreasing water supply

B. desertification

C. factors limiting crop productionD. developing efficient plants

D. developing efficient plants

1
5 tháng 5 2017

Đáp án D
Toàn bài nói về việc mùa màng càng bị kém hiệu quả do thiếu nước nhưng đã tìm ra những loại cây chịu
hạn thay thế để sản xuất ra những vụ mùa tốt hơn. Từ việc nêu ra các đặc điểm chịu hạn của chúng tác giả
kết luận những loại cây thay thế này đang được nghiên cứu phát triển