i just don't understand___that prevents so many Amerians from being as happy as one might expect.为什么是What it is

问题描述:

i just don't understand___that prevents so many Amerians from being as happy as one might expect.
为什么是What it is

这是宾语从句,应该用陈述句语序(主谓)。从句缺主语,应该补上,就是what。
翻译:我只是不明白,是什么让那么多美国人不能过的想希望的那样开心。

这是强调句型特殊疑问句用在了宾语从句中,用陈述语序.
It Is+被强调部分+that+其他
when is it that …….