We are using up our natural resources too quickly and at same ti

We are using up our natural resources too quickly and at same time we are _____our environment with dangerous chemicals.
A、protecting
B、saving
C、polluting
D、fighting
【正确答案】：C
【题目解析】：本题考查动词辨析。句中and at the same time表示递进，所以选择pollute合乎逻辑。