(一).How did it happen? 这是怎么回事？

原音重现：

A：I heard that Willis died last week.
我听说威利斯上周去世了。
B: That's terrible. How did it happen?
太让人吃惊了。怎么会这样？

(二).What's going on?出什么事了？

原音重现：

A：What's going on? I see a lot of police.
出什么事了？那么多警察。
B: I think someone robbed the bank.
可能有人抢银行了吧。