96. -- ____ have you been married？ -- For twenty years.
A. How far B. How often C. How long
97. If you sit in a chair ____ a long time, your back may begin to hurt. A. in B. on C. for 98. -- I often have hamburgers for lunch.
--You’d better not. It’s bad for you ____ too much junk food. A. eat B. to eat C. eating
99. My best friend Tom is ____ honest boy. You can believe him. A. a B. an C. the
100. – Is Mr. Smith still in Shanghai? -- Yes, he ____ there for two months.
A. has been B. has gone C. has been to