WE CAN'T CLEAN UP OUR ... RIVERS AND SEAS OVERNIGHT.A. POLLUTING B...

21. - BÀI SOẠN UNIT 10: CONVERVATION
BÀI SOẠN UNIT 10: CONVERVATION

21.

We can't clean up our ... rivers and seas overnight.

A. polluting

B. pollute

C. pollution

D. polluted