When I try to understand ______ prevents so many Americans from being as happy as one might expect ,it seems to me that three are two causes.A.why it doseB.what it doesC.whatD. why it is还请大家解释一下

是否选C?

C

A,B后面接原型吧,D后面不接第3人称吧

哦 谢谢有没有谁能翻译一下这句话的意思？

c.试译：我不知道为什么那么多美国人并非我们想的那么开心，我想原因可能有两个。

C