Question

7. When I try to understand        that prevents so many Americans from being as happy as one might expect,it seems to me that there are two causes (be)

当我试图去了解为什么如此多的美国人不能与想象中的那样幸福时，我认为有两个原因。

Answer 1

7. what it is understand后跟的是一个宾语从句，从句应用陈述语序;从句里又含有一个强调句型。