a代表一个数,但不是0。
a+a÷a=( ) (a+a)÷a=( )
a+1;2
Tom _____ not be murderer (凶手) because I saw he was at other place at that time(在那时).[ ]
A. must
B. can
C. is
D. will
《药品流通监督管理办法》施行的时间是()。
A.[2001-12-1]
B.[2002-8-4]
C.[2002-9-15]
D.[2007-5-1]