C-7：catch sb. on the hop 使某人措手不及
A:It's a great pity he left suddenly.
A:他突然走了，真叫人遗憾。
B:Yeah, He caught us on the hop.
B:是啊，真让我们措手不及。
A:He has lost a good chance to understand others.
A:他失去了一次了解他人的好机会。
B:Perhaps you're right.
B:也许你是对的。
