Correct

在行

/ zàiháng /
Strokes

Definition

to be adept at sth/to be an expert in a trade or profession

Example

As a Verb

be expert at/in/on sth; know one's stuff; know the ropes

1
Zuò
shēng
生意
bu
zàiháng
在行
  

I'm no expert at business.

2
Xiū
diàn
电器
hěn
zàiháng
在行
  

He is very good at repairing electrical appliances.

3
duì
jiàoxué
教学
hěn
zàiháng
在行
  

He knows the ropes about teaching.

4
hěn
zàiháng
在行
  

You are very expert at it.