—Whowillberesponsiblefortheseriousairpollution?—Everybo...

問題詳情：

—Who will be responsible for the serious air pollution?

—Everybody should try his best to protect the environment ___it is too late．

A．after         B．until        C．when     D．before

【回答】

D

知識點：連詞

題型：選擇題