题目

As a student, he is ________ to work hard to keep up with his classmates. A . expected B . known C . suffered D . hoped 答案：A血液的组成包括（　　）A.红细胞和血浆B.红细胞、白细胞和血小板C.血细胞和血浆D.血浆、血细胞和红细胞