–Withthefailureoftheexperiment,wehavereachedadeadend.-...

問題詳情：

  –With the failure of the experiment, we have reached a dead end.

--Cheer up! Many good things would never have happened if the bad events       first.

A. don’t happen     B. didn’t happen    C. hadn’t happened     D. haven’t happened

【回答】

C

知識點：動詞時態與語態

題型：選擇題