第三代化学消毒剂的代表是()。
A.甲醛
B.臭氧
C.戊二醛
D.环氧乙烷
E.过氧乙酸
参考答案:C
.________ relation between China and Russia has developed steadily since Vladimir Putin was reelected ________ president last May.
A.The; the
B.A; the
C.The; /
D.A; /
那些没有变成产成品、同时经济价值很小的投入材料被划分为:
A.废料。 B.废品。C.次品。 D.损耗。