A:﹣3
B:﹣1
C:3
D:4
最早和最大的奴隶贩子分别是( )
化合物
NaF
MgF2
MgO
SiF4
SiO2
熔点/K
1266
1534
3125
183
1983
摩氏硬度
3,2
6.0
6.5
7
Judging from the message they convey, these two chapters are __________ independent of each other, that is, they are not in connection with the other at all.