---Whydoesthelakesmellterrible?---Becauselargequantitie...

問題詳情：

--- Why does the lake smell terrible?

---Because large quantities of water        .

A．have polluted                                      B．is being polluted

C．have been polluted                                  D．has been polluted

【回答】

C

知識點：動詞時態與語態

題型：選擇題