一、单项选择。
1.-----Learning English well is _______.
------ Yes, but it will become much easier if you ___________.
A. hard work ; hard work B. hard work ; work hard
C. a hard work; hard work D .a hard work ; work hard.
2.The twins ______ China since their father came to work in Shanghai.
A.have been to B.have gone to C.have been in D.have been
3._____ great fun it is ______ tricks on those boys.
