C.interestingly D.interestedly 

　　2)My brother saw the children ___________ near my house when he went to work at 8:00.

　　A.play B.playing

　　C.to play D.be playing 

　　3)He told me that raising pigs ___________ his job.

　　A.are B.were

　　C.have been D.is 

　　4)When I think of the __________ problem,I feel __________.

　　A.puzzled;puzzled B.puzzling;puzzling

　　C.puzzling;puzzled D.puzzled;puzzling 

　　5)The girls were noticed ___________ with each other at this time yesterday.

　　A.quarrel B.quarreling

　　C.to be quarreling D.quarreled 

　　答案与解析:

　　1)A　表示"某人对某事感兴趣"要用interested。

　　2)B　see sb.doing sth.的意思是"看见某人在做某事"。

　　3)D　动词-ing形式作主语时,看作单数形式。

　　4)C　puzzling的意思是"令人困惑的",多修饰事情等;puzzled的意思是"困惑的",多修饰人。

　　5)B　现在分词作宾语补足语时,变成主语补足语时,仍用现在分词。