scar
疤痕    

例句：
He bared his left knee to display surgical scars from football injuries.
他露出左膝，可看到他在足球运动中受伤的疤痕。

brush up
复习；温习
 
例句：
Before the exam, I must brush up on my Franch Grammer.
考试前我必须复习一下法语语法。
 

I'll think it over.
我要仔细考虑一下。 

对话：
A: Kate, do you want to go with me to New York?
B: I can't promise you. I'll think it over.
A: All right. It's up to you to make your own decision.

A：凯特，你想和我一起去纽约吗？
B：我不能向你保证。我得仔细考虑一下。
A：好吧，由你自己决定。