Choose the best answer

1. The .................. of water pollution is the death of many types of fishes.
A. cause     B. effect      C. reason     D. solution
2. Rising sea level can make some cities .................
A. pollute       B. exchange     C. appear        D. disappear
3. Protecting the ................environment is saving human life
A. natural    B. polluted     C. working     D. All are correct
4. Many students ................... aerobics to keep fit.
A. have    B. go      C. play      D. do