put their back up

基本解释

They always lean back and put their feet up on the seat in front of them.
他们总是背靠着椅子，把脚放在前排的椅子上。
Before the day ended, everybody made up their minds to put back up their false front tomorrow.
一天结束前，大家决定明天还是继续戴着面具上班。
Before I left, I picked up their cross and put it back in place on their tomb. The break was clean so it fit like a puzzle piece.
离开之前，我捡起他们的十字架重新放回去，断裂的痕迹一目了然，因此看上去就像是个拼图一样。

What they are hoping to do is to come up with a coordinated plan to ease the recession, get their economies back on track and put in place regulatory measures to try to prevent similar crises in future.

But as I said the other night at my press conference, I'm a big believer in the idea of persistence -- the idea that when the American people put their mind to something and keep at it, without giving up, without turning back, no obstacle can stand in our way, and no dream is beyond our reach.
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Additionally, gold is being held back by some market worries that countries such as Greece and Portugal may have to put up some of their gold reserves as security in order to gain additional loans, Gero said.
FORBES: Gold Strong In Euro Terms But Faces Offsetting Factors Against Dollar