问题补充:
Since I knew how hard the life they lead is, I have understood they need so much money.
A. how
B. why
C. whether
D. when
答案:
A. how
(答案→)B. why
C. whether
D. when
解析:考查连接副词:A. how怎样B. why为什么,C. whether 是否,D. when什么时候,句意:自从我知道他们的生活有多难,我一直理解他们为什么要这么多钱。选B。