back up

基本解释

Because congestion prevents ships heading back to pick up new cargoes, it has helped to push prices up further.
由于拥堵使船只难以返回运载新的货物，起到了进一步推高价格的作用。
Some drivers will switch to the bridge to shorten theircommute, but as the traffic builds up there the motorway starts to look like abetter bet, so some switch back.
一些司机为了缩短行程选择走桥，但当桥上变得拥堵时，高速路似乎是更好的选择，因此一些司机又折返回来走桥。
The fire won't burn because the flue is blocked up.
因烟道堵塞火烧不起来。
Clogged pipes backed up drain water.
阻塞的水管堵塞了沟水。

If someone or something backs up a statement, they supply evidence to suggest that it is true.
If you back up a computer file, you make a copy of it that you can use if the original file is damaged or lost.
If an idea or intention is backed up by action, action is taken to support or confirm it.
If you back someone up, you show your support for them.
If you back someone up, you help them by confirming that what they are saying is true.
If you back up, the car or other vehicle that you are driving moves back a short distance.
If you back up, you move backward a short distance.
When a car backs up or when you back it up, the car is driven backward.
&rarrsee also backup