题目内容
【题目】Why are you here? You are supposed to ________ the experiment in the lab.
A. perform B. be performing C. have performed D. be performed
【答案】B
【解析】考查时态。句意：你为什么在这里？你应该正在实验室里做实验。表示“正在做某事”用进行时态，故选B项。
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题目内容
【题目】Why are you here? You are supposed to ________ the experiment in the lab.
A. perform B. be performing C. have performed D. be performed
【答案】B
【解析】考查时态。句意：你为什么在这里？你应该正在实验室里做实验。表示“正在做某事”用进行时态，故选B项。
