A:2+(x+2)=3(x−1)
B:2−x+2=3(x−1)
C:2−(x+2)=3(1−x)
D:2−(x+2)=3(x−1)
族
周期
IA
0
1
①
II A
III A
IV A
V A
VI A
VIIA
2
②
③
⑥
Ne
3
④
⑤
Al
S