Which of the following statements is true?
A.
Carbon monoxide is a greenhouse gas
B.
The United States has effectively controlled its greenhouse gas emissions
C.
Emission of greenhouse gases by various countries is proportional to the size of their population
D.
Global warming is caused by greenhouse gases
I believe my best choice is D not entirely sure
2 answers
D is correct, but so are others. What do your text materials say?
I think D is the best answer
1 answer