Question

He made a mistake, but then he took action to change the situation ________ it got worse.

A．until

B．when

C．before

D．because

Answer 1

C

解析试题分析：句意：他犯了一个错误，但他在它变得更糟前采取了行动改变现状。Until直到；when当···时；before在···之前；because因为。根据句意可知选C。
考点：考查连词。