在含有Cu(NO3)2、Mg(NO3)2和AgNO3的溶液中加入适量锌粉,首先置换出的是( )
A.Mg
B.Cu
C.Ag
D.H2
答案:C
通常,将软件产品从提出、实现、使用维护到停止使用退役的过程称为 【4】 。
A.(A) Someone from the housing office will fix the toilet.
B.(B) Peter will phone the housing office for you.
C.(C) You can fix the toilet in the bathroom by yourself.
D.(D) Peter will repair the toilet in the bathroom.