Đối với những vùng đất trống, đồi núi trọc thì biện pháp chủ yếu và cần thiết nhất là:
A.Tiến hành chăn thả gia súc
B.Trồng cây gây rừng
C.Cày xới để làm nương, rẫy để sản xuất lương thực
D.Làm nhà ở

Mark the letter A, B, C or D to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions
We have to suffer from traffic congestion and pollution every day
A.crowd
B.mass
C.accident
D.fullness

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
In the ______________agriculture, farmers try to limit the use of chemicals and fertilizers.
A.conserving
B.preserving
C.supporting
D.sustainable

Mark the letter A, B, C or D to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions
For environment safety, we need to find ways to reduce emission of fumes and smoke of factories.
 
A.leak
B.poison
C.pollutant
D.release

Mark the letter A, B, C or D to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions
We can protect many species by keeping them in wildlife reserves.
A.protected land
B.saved land
C.park
D.zoo

Mark the letter A, B, C or D to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions
The advances of commercial airplanes resulted in a shrinking world.
A.reduced
B.smaller
C.compressing
D.decreasing

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
 
I don’t choose this flat because it seems to have so much _____________, which is so bad for my health.
A.mould and mildew
B.asthma
C.mushroom
D.sunlight

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
 
Nowadays, people are searching for more ____________________materials to build their houses.
A.environmentally-friendly
B.environmental-friendly
C.environments-friendly
D.environmental-friend

Cho hình chóp $ S.ABCD $ có đáy là hình vuông. $ SA $ vuông góc với đáy. Góc giữa đường thẳng $ SC $ và mặt phẳng $ \left( ABCD \right) $ là
A.$ \widehat{ASC} $ .
B.$ \widehat{CAS} $ .
C.$ \widehat{SCB} $ .
D.$ \widehat{SCA} $ .

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
 
It is recommended that we clean our house at least once a week to remove dirt and keep airflow ______________ in our house clear.
A.pathways
B.chemicals
C.products
D.journeys