2019年mpa考试英语真题——连词1647

{01} The new system needs to be in operation for five months ________ it can be updated. A.as B.while C.before D.once 解析：C考察状语从句。本句的before用语肯定句中，强调主句动作持续的时间比较长，意为：要多多久….才。故C正确。
本题选C。
{02} The woman rushed out ________ she felt the house shaking. A.until B.immediately C.unless D.before 解析：B B考察状语从句。英语中的immediately，instantly, directly等副词可以作为连词，引导时间状语廵，相当于as soon as。
本题选。