杀灭所有的微生物称为（）
A.消毒
B.抗毒
C.抗菌
D.无菌术
E.灭菌
参考答案：E
手持式PH计校正时应先用PH值为（）的校正液进行校正。
A、1
B、4
C、7
D、9
________is impossible to learn a foreign language well in such a short time.Rome was not built in one day.[ ]
A. This
B. It
C. That
D. Which
