Moreandmorepeoplehaverealizedthatwewon’thavecleanerwate...

問題詳情：

More and more people have realized that we won’t have cleaner water to drink unless something _______soon.

A. is done   B. was done   C. will be done   D. to be done

【回答】

A

知識點：動詞時態

題型：選擇題