-- It's a wise to wear the white tie. It matches your shirt well.
-- Thank you very much.
A:choice
B:support
C:mixture
D:honour
计算 a÷ • 的结果是( ).
如图是氧化汞分子分解示意图.从示意图中,你能够得出的规律或者结论有:(答出两条即可)
①____.②____.