Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
The ………. is a natural process that warms the Earth’s surface.
A.greenhouse fever
B.heating effect
C.boiling system
D.greenhouse effect

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
Sulphur dioxide is a ………. and a major contributor to acid rain.
A.pollutant
B.fertilizer
C.pesticide
D.device

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
In agriculture, farmers often add ………. to enrich the soil.
A.waste
B.flavors
C.fertilizers
D.pesticides

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
_____ is the current increase in the temperature of the Earth's surface (both land and water) as well as its atmosphere.
A.Global drought
B.Global warming
C.World heating
D.World fever

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
Environmentalists would like to see ………. replaced by renewable energy sources.
A.fossil fuels
B.green energies
C.eco-energies
D.greenhouse effects

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
The land loses its protective cover of ………. and soon turns into desert.
A.animals
B.soil
C.clothing
D.vegetation

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
If we continue to ………. the earth's natural resources, we will cause serious damage to the environment.
A.conserve
B.preserve
C.save
D.deplete

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
Smoking is likely to ………. your health permanently.
A.pollute
B.damage
C.propose
D.benefit

Tinh trùng di chuyển vào tử cung, rồi vào âm đạo với tốc độ trung bình khoảng
A.3mm/s.
B.3mm/phút.
C.30mm/phút.
D.30mm/s.

Vỏ của trùng lỗ được cấu tạo từ
A.xenlulozơ.
B.cacbon.
C.đá vôi.
D.Không có vỏ.