Cathy said she speak four languages.[ ]
A. may
B. could
C. would
D. can
答案:B
A.Fe2(SO4)3=2Fe+3+3SO4-2
B.CuCl2=Cu2++Cl2-
C.NaOH=Na++OH-
D.Ba(NO3)2=Ba2++2(NO3)2-
会计档案的定义是什么?