We’ve just installed two air-conditioners made in Shanghai in our apartment, ________ should make great differences in our life next summer．
A.whichB.whatC.thatD.they在线课程A
解析：

试题分析：本题考查关系代词的用法。详细
解答：这是一个非限制性定语从句，此处缺少一个关系代词；由于该非限制性定语从句先行词是air-conditioners，所以关系代词应用which。