It was in the labwas taken charge of by Johnsonthey did the experiment.A. where; whichB. w

问题补充：

It was in the labwas taken charge of by Johnsonthey did the experiment.

A. where; which

B. which; that

C. which; which

D. that; which

答案：

A. where; which

(答案→)B. which; that

C. which; which

D. that; which

解析：第一空是which引导的定语从句，先行词是lab，which在定语从句中主语。第二空是that，是强调句型里的that。这是强调句型其结构是It was+被强调部分+ that+其他，判断强调句型的方法是把It was that去掉整个句子不缺成分，是成立的。