Living in the central Australian desert has its problems, _____

单选题 Living in the central Australian desert has its problems, ______obtaining water is not the least．

A．of which
B．for what
C．as
D．whose

参考答案A

解析: A。在澳大利亚中部的沙漠居住有很多问题，不单单是取水难。
考查定语从句。逗号后为非限定性定语从句，又有“其中”之意，所以ofwhich最为合适。

单选题 It is better to die on one's feet than ________

A．living on one's knees
B．live on one's knees
C．on one's knees
D．to live on one's knees

单选题 They ________to enter the building by the back door; however, the back door was locked．

A．weren't supposed
B．wouldn't be supposed
C．were supposed
D．would be supposed

单选题 There was a ．knock at the door．It was the second time someone ________me that evening．

A．had interruped
B．would have interrupted
C．to have interrupted
D．to interrupt