I am very tired today. I _____ go to bed early.[ ]
A. should
B. shouldn't
C. can
D. can't
答案:A
得过麻疹的人以后不再的麻疹,是因为体内存留有
A.抗原
B.吞噬细胞
C.抗体
D.溶菌酶
计量员有哪些行为要追究责任,给予行政处分直至诉诸法律解决?