碱
酸
盐
碱性氧化物
酸性氧化物
A
Na2CO3
H2SO4
NaOH
SO2
CO2
B
HCl
NaCl
Na2O
CO
C
CH3COOH
CaF2
D
KOH
HNO3
CaCO3
CaO
A:A
B:B
C:C
D:D
六年级男生人数是女生的 54 ,女生人数是男生的____,男生人数是全年级的____.
如图是植物细胞与动物细胞示意图,请据图作答:
设U为全集,A,B是集合,则“存在集合C使得A⊆C,B⊆∁UC”是“A∩B=∅”的( )
A. Enjoy your meal!
B. And to drink?
C. Can I help you?
D. How much is it?
E. Here you are.
A:____
B:I want some rice.
B:A box of milk for me,please.
A:That's some rice and a box of milk.
B:____
A:It's ten dollars.
A:Thank you. ____