1.多达
I can take up to four people in my car.
我的汽车最多能坐四个人.
2.直到
Up to now he's still quiet.
他直到现在仍保持沉默.
3.在于…,取决于…
This is up to you.
这件事取决于你.
4.能胜任
He's not up to the work.
他不能胜任这件工作.
5.做…,忙…
What's he up to?
他做什么呢?