The river beyond our school has become clean again as new measures are ______ to prevent it ______ any further.

   A. taken; polluting                   B. taking; being polluted

   C. taken; being polluted            D. taking; to be polluted

The river beyond our school has become clean again as new measures are ______ to prevent it ______ any further.

A．taken; polluting                              B．taking; being polluted

C．taken; being polluted                          D．taking; to be polluted