题目内容
The pipes have oil or water, which is heated and sent to the storage tank until to produce electricity.
A. needed B. needing
C. to need D. having needed
A
【解析】
试题分析:考察时间状语从句中的省略。当状语从句的主语与主句的主语一致时,可以省略状语从句的主语和系动词be 。将省略还原该句应该是sent to the storage tank until(it is)needed to produce electricity.句意:该管道内有油或者水,直到需要发电时,其才会被加热并送入存储罐中。
考点:考察时间状语从句中的省略。
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