twice, the postman refused to deliver our letters unless we changed our dog. A.

 ____twice, the postman refused to deliver our letters unless we changed ourdog.  

A. Beingbitten     B. Bitten  

C. Havingbitten    D. To be bitten  

试题答案

【答案】

 B。  

【解析】考查分词的用法。The postman与bite之间是被动和完成的关系，所以答案为:B。