up against
1.与某物接触in close contact with sth
He is leaning up against the wall.他靠着墙。
2.面临faced with
They are up against starvation.他们正面临饥饿。


up and about
下床活动out of bed and active again
He will be up and about this afternoon.他下午就能起床活动了。
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up and down
上上下下a higher and lower
She was jumping up and down.她上上下下地蹦着。
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up for
打算…intended or being considered for
How long has that house been up for sale?那房子提出变卖已多久了?
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up to
1.多达as a maximum number or amount
I can take up to four people in my car.我的汽车最多能坐四个人。
2.直到as far as sth
Up to now he's still quiet.他直到现在仍保持沉默。
3.在于…,取决于…the duty or responsibility of sb
This is up to you.这件事取决于你。
4.能胜任capable of sth
He's not up to the work.他不能胜任这件工作。
5.做…,忙…occupied or busy with
What's he up to?他做什么呢?

They stood up when he came in.当他进来时,他们都站起来。
He got up very late.他起床起得很迟。
Please lift your head up.请把头抬起来。
She lives up North.她住在北部。
We finished all works up.我们完成了所有的工作。
He tore up the clothes.他把衣服撕碎了。
We divided up the money.我们把钱分了。

1.up也可用作形容词作“向上的,上行的”解。例如:
He caught the up train.他赶上了上行的火车。
2.up还可用作动词,意为“站起身,提高(价格等)”解。例如:
He upped and left.他站起身走了。
You simply couldn't up it.你根本不能提高了。

up用作介词的意思是“向…上,向〔在〕…的顶上”。还可表示“往…的上端,向…的较高处,顺着…向上〔北〕; 往〔在〕…的上游〔发源地〕,在…”。up常指街道等长度远远超过宽度。

up and down
在…上走来走去a higher and lower on
He is walking up and down the platform.他在站台上走来走去。

There was a workman up the ladder.有一个工人在梯子上工作。
He's up the school.他在学校里。
They climbed up a hill.他们爬上了山。
She walked up the street.她沿街走去。
The ship is sailing up the Nile.这艘船顺尼罗河向上游航行。

［词源］＜古英语upp(向上,向…上)