Question

Not until the press reported the pollution _________ why the water supply had been cut off.

A．people did know	B．people had known
C．did people know	D．had people known

Answer 1

C

試題分析：not until 位于句首，句子使用部分倒裝。排除ＡＢ，Ｄ答案時態(tài)不對。句意：
直到新聞報道了污染人們才知道為什么水的供應被切斷。
點評：倒裝分為部分倒裝和完全倒裝。要分清他們的概念及使用規(guī)則。部分倒裝是把部分謂語（ｂｅ動詞／助動詞／情態(tài)動詞）提到主語前面，完全倒裝是把整個謂語提到主語前面。