The phrase “do this” in the first paragraph mostly means ______.

A. predictable

B. unpredictable

C. changeable

D. unchangeable

A. reduced considerably

B. put a tick

C. examined carefully

D. motivated to develop

A. a kind of harmless animals

B. an achievement of human beings

C. a harmful factor to the environment

D. a kind of useful plants

A. chamber

B. flat

C. area

D. studio

A. Environment pollution is real.

B. Reasons why low-lying areas are flooded.

C. Solutions to global warming.

D. Reasons why global warming is a problem.

A. higher temperature

B. coastal erosion

C. increasing sea level

D. stable rainfall