问题
I just don’t understand_______ that prevents so many Americans from being as happy as one might expect.
A:why it does
B:what it does
C:what it is
D:why it is
B:what it does
C:what it is
D:why it is
正确答案是：
同类题型
If I ruled the world, I would ______ the world ______ wars and killers.
Where have you _______ all day— I came back at noon and I _______ in this officesince then.
Many of us who have never been to Egyptalways associate Egyptthe ancient pyramids.
Lily, look at the flowers in the garden.— Wow, _______ beautiful they are!