分解因式a-ab2的结果是[ ]
A.a（1+b）（1-b）
B.a（1+b）2
C.a（1-b）2
D.（1-b）（1+b）
答案：A
给下列句子排序。
( ) Did you read books?
( 1 ) What did you do yesterday?
( ) Did you clean your room?
( ) I went to the park.
( ) No, I didn't clean my room.
( 6 ) Yes, I read some books.
引起成年人急性黄疸型肝炎最主要的病原为
A．HAV
B．HBV
C．HCV
D．HDV
E．HEV
