Question 1: ___________is the gradual increase of temperature on the earth's surface due to greenhouse effect.

A. Global warming B. Climate change C. Natural habitats D. Extreme weather

Question 2: Air pollution is a major ___________that has serious effects on our health.

A. measure B. solution C. issue D. sewage

Question 3: Some animals lose their habitats because of ___________.

A. habitat B. energy C. deforestation D. biodiversity

Question 4: Although we are aware _______ the importance of environment, we still overexploit it.

A. from B. on C. for D. of