Chọn câu trả lời đúng nhất để điền vào chỗ 3 chấm và nếu bạn nào giỏi môn anh thì giải thích giúp mình vì sao lại chọn với ạ J :
1. Nuclear energy is … , but it is dangerous .
A. Renewable B. non-renewable C. natural resource D. fossil fuel
1. fossil fuels are very common in our society but they … the environment .
A. Waste B. pollute C. renew D. provide
2. All the house in our village will be … by solar energy .
A. Frozen B. widened C. heated D. heightened
3. Several governments try to … the use of fossil fuels .
A. waste B. save C. reduce D. increase
4. at this time next week , we … a wind turbine in our garden .
A. will installed B. will be installing C. install D. installed
5. low energy light bulbs should be used to … electricity .
A. convert B. save C. spend D. buy
6. it is a good idea to use … when travelling long distances .
A. private cars B. public transport C. cars D. taxis
7. “why is it called a … source ?” – “ because it can be replaced easily and quickly ”.
A. renewable B. non-renewable C. effective D. specific
8. we must … the amount of water our family use every day .
A. lessen B. narrow C. lower D. reduce
9. wave energy is a source of … energy .
A. environmental friendly B. environmentally friendliness
C. environment friendly D. environmentally friendly
11. alternative sources of energy … developed in the near future .
A. has been B. will be C. is D. was
12. she … cooking in the kitchen at 7 PM tomorrow .
A. will B. is C. will be D. be
13. some new energy-saving bulbs … in the dining room .
A. will be put B. will put be C. will put D. will be putting
14. what should we do to … electricity ?
A. take B. save C. cut D. waste
15. the wind , the sun , and the wave are some types of … sources of energy .
A. cheap B. costly C. changeable D. alternative
Cảm ơn các bạn trước vì đã giúp mình nhé J
A. \(x^2\) ≤ \(3x\Leftrightarrow\) \(\frac{x^2}{x}\)≤\(\frac{3x}{x}\) \(\Leftrightarrow\) \(x\) ≤ 3
(Sai.Vì \(x\) không khác 0 nên không thể chia 2 vế cho \(x\))
C.\(\frac{x+1}{x^2}\ge0\) \(\Leftrightarrow\) \(x+1\ge0.x^2\Leftrightarrow x+1\ge0\)
(Sai.Vì x không khác 0 nên không thể nhân cả 2 vế với \(x^2\))