Question

【题目】If you become rich, you will have a difficult time (know) who your real friends are.

Answer 1

【答案】knowing
【解析】句意：如果你有钱了，你会在知道谁是你真正的朋友上犯难。同样也是考查固定搭配，have a difficult(hard) time doing sth做某事有困难，故用knowing。