If you want to get good grades you need to pull your socks up. At this rate you might not graduate.
He's not playing well at the moment. He needs to pull his socks up if he wants to get into the first team.
I expect more from you. You need to pull your socks up and help out more around the house. You know your mother's not very well.
动词短语 pull up 的意思是车辆或其它交通工具在特定的地点停下来。
The bus pulled up at the stop only 25 minutes late.
A car's just pulled up outside. Can you see who it is?