![](https://rs.olm.vn/images/avt/0.png?1311)
—
C
H
2
—
C
C
H
3
|
=
C
—
C
H
2
—
k
↔
C
5
k
H
8
k
→
+
S
2
C
5
k
H
8
k
S
2