1 . There is a large ____________ of animals that live in Nairobi National Park . ( vary )
Điền đúng dạng từ trong ngoặc !!!
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There is a large... of animals that live in Nairobi National Park A various B varied C variety D vary
VI. Provide the correct form of the words in capital letters to complete the sentences.
26. There is a large ______variety____ of animals that live in Cuc Phuong National Park. (VARY)
27. Artists are ____creative______ people (CREATE).
28. He works as a ____mechanic______ in this factory. (MACHINE)
29. Reading funny stories is an _______enjoyable___ way to relax. (ENJOY) 30. The newspaper is a means of _______communication________ (COMMUNICATE)
Question 26: There is a large variety of animals that live in Cuc Phuong National Park.
Question 27: Artists are creative people.
Question 28: He works as a machinist in this factory.
Question 29: Reading funny stories is an enjoyable way to relax.
Question 30: The newspaper is a means of communication.
1. He apologized for the (convenient)_inconvenience___ he had caused.
2. For your (inform)_information__, the library is on the third floor.
3. This is one of the best (document) _documentary___films showing the lives of working people.
4. The government has introduced some (effect)_effections__ measures to reduce unemployment.
5. He is a (curiosity)_curious__boy. He is always asking questions.
6. There is a large __variety__ of animals that live in Nairobi National Park. (vary)
7. We can't clean up our__polluteed_ rivers and seas. (pollute)
8. The earth is being_threatened__ and the future looks bad. (threat)
9. His__survival_ is still uncertain;he has been seriously injured. (survive)
1,He verry ............. He has a lot of friends
2,We live in a .........................
3,There is big ................... in her bedroom ( 3 câu này mình ko có bảng thì không làm được )
2.Điền dạng đúng của động từ trong ngoặc vào chỗ chấm
1,They (watch)...are watching.................TV now
2,Ha(not do)......isn't doing.......... Homework now
3,They(live) .........live........ in town house
4,He(not,play)..........isn't playing........a game.He is writing an email to his friend
5,She(watch) ...watches...............TV everyday
Cho dạng đúng của động từ trong ngoặc:
1. He is engrossed in doing(science)..scientific.............. research.
2. Oil spills are a great(threaten)......threat............ to the undersea world.
3. He wants(width)...widen............. his knowledge of the subject.
4. You may be surprised at the large(varied).....variety............. of animals in national parks.
1 . There is a large varity of animals that live in Nairobi National Park .
đang chờ ý kiến đóng góp
\(\sqrt{x^2-2m}+2.\sqrt{x^2-1}=x\ge0\)
đkxd: \(x^2\ge2m,1\)
Ta có: \(\sqrt{x^2-2m}+2.\sqrt{x^2-1}=x< =>\text{}\text{}\text{}2.\sqrt{x^2-1}=x-\sqrt{x^2-2m}\)
=>\(4.\left(x^2-1\right)=\left(x-\sqrt{x^2-2m}\right)^2\)và \(x-\sqrt{x^2-2m}\ge0< =>x\ge\sqrt{x^2-2m}< =>m\ge0\)
<=>\(4x^2-4=x^2-2x.\sqrt{x^2-2m}+x^2-2m\)
<=>\(2x^2+2m-4=-2x.\sqrt{x^2-2m}\)
<=>\(x^2+m-2=-x.\sqrt{x^2-2m}\)
=>\(\left(x^2+m-2\right)^2=\left(-x\sqrt{x^2-2m}\right)^2\)và \(x^2+m-2\ge0\)
<=>\(x^4+2.\left(m-2\right)x^2+\left(m-2\right)^2=x^4-2m.x^2\)
<=>\(\left(4m-4\right)x^2=-\left(m-2\right)^2\)
-xét m=1=>pt<=>0.x^2=-1(vô lí, loại)
-xét m khác 1
=>\(x^2=\frac{-\left(m-2\right)^2}{4m-4}\)
+Với m>1=>\(x^2=\frac{-\left(m-2\right)^2}{4m-4}< 0\)(vô lí, loại)
+Với 0<_m<1=>\(x^2=\frac{-\left(m-2\right)^2}{4m-4}>0< =>\orbr{\begin{cases}x=-\sqrt{\frac{-\left(m-2\right)^2}{4m-4}}\\x=\sqrt{\frac{-\left(m-2\right)^2}{4m-4}}\end{cases}}\)
Theo điều kiện xác định=>x^2>_1,2m và x^2>_2-m
=>\(\hept{\begin{cases}\frac{-\left(m-2\right)^2}{4m-4}\ge1\\\frac{-\left(m-2\right)^2}{4m-4}\ge2m\end{cases}and\frac{-\left(m-2\right)^2}{4m-4}\ge2-m}< =>\hept{\begin{cases}\frac{\left(m-2\right)^2}{4-4m}\ge1\\\frac{\left(m-2\right)^2}{4-4m}\ge2m\end{cases}and\frac{\left(m-2\right)^2}{4-4m}\ge2-m}\)Vì 4-4m>0=>\(\hept{\begin{cases}\left(m-2\right)^2\ge4-4m\\\left(m-2\right)^2\ge2m\left(4-4m\right)\end{cases}and\left(m-2\right)^2\ge\left(4-4m\right)\left(2-m\right)< =>\hept{\begin{cases}m^2\ge0\\\left(3m-2\right)^2\ge0\end{cases}}}\)và 2/3<_m<_2
Do đó để pt có nghiệm thì 2/3<_m<1