be good at本身即短语。
be good atv.善于；
例如If you only listen to what others speak, you will be good at listening.
What makes you think you will be good at this?
什么让你想到你会做得很好。
The important thing is to be good at learning.
重要的是善于学习。
You must be good at learning at first.
你必须首先擅长学习。
