题目内容
It hasn't been made clear ________ the new underground line is to be open to traffic.
| A.when | B.that |
| C.what | D.where |
A
A 考察名词性从句。这是when引导的主语从句,it是形式主语。句意:新的地铁线路何时开放还不清楚。故A正确。
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题目内容
| A.when | B.that |
| C.what | D.where |