when I try to understand___it is that prevents so manyAmericans from being as happy as one might expect,it seems to me___there are quite a few causes.A why ;that B which ;as C what ;that D whether ;since
问题描述：
when I try to understand___it is that prevents so many
Americans from being as happy as one might expect,it seems to me___there are quite a few causes.A why ;that B which ;as C what ;that D whether ;since
答
选C，What it is......是做understand的宾语，而后面that引导的是主语从句
答
C
答
C 当我试图去理解是什么阻挡了许多美国人得到他们应有
的快乐时,我发现个中原因实在不少.
what it is that prevents...
that 跟随what it is,概括阻挡美国人得到快乐的原
因.这里不能用why,因为why prevents说不通,而
what prevents就没有问题.
答
A
用why引导状语从句 表原因
用that引导的状语从句 是个连接词