(单选题)

—Did you have any difficulty catching yesterday’s lecture?
—No. The professor spoke very clearly to make his speech easy ______.

A.understood

B.understand

C.understanding

D.to understand

参考答案：D

参考解析：

考查主动表被动。句意：—昨天的课你听的时候有困难吗？—没有。那个教授说话很清楚，以便他的演讲容易理解。make+宾语+adj.+ to do句型，这里的不定式是主动表示被动。故选D。

知识点：

—Did you have any difficulty catching yesterday’s lecture?—No. The professor spoke very clearly to make his speech easy ______.