THE ENVIRONMENT PRACTICE TEST 1I. CHOOSE THE WORD OR PHRASE THA...

1. - 200 CAU TRAC NGHIEM KQ ANH 9 -BAI 6-7
200 CAU TRAC NGHIEM KQ ANH 9 -BAI 6-7

1. _______ air is one of the many problems we have to solve.

a. Pollution

b. Polluted

c. Polluting

d. Pollute