on the latch

基本解释

At any rate, the era of leaving the front door on the latch is over.
不管怎么说，前门虚掩不落锁的时代是一去不复返了。
He leant against the side, and held his fingers on the latch as if intending to open for himself.
他斜靠在屋边，手指握着门闩，好像打算自己要开门似的。
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I don't know if that was a local term or if it is universal; "on the latch" meant the door was closed but not locked.
我不知道这是当地的一种说法还是大家都这么说；"不落锁"的意思是掩上门，但不锁住。

So basically, if we were to place a baby on the mother's abdomen, the baby would actually crawl up the mother's chest and choose which breast it would like to latch on to.
Dr.Vallenas says many mothers are discouraged from breast-feeding because they do not know how to get their baby to latch on properly to the breast's nipple, or because they suffer pain and discomfort.

Much like the ASUS Transformers, undocking the tablet was only a matter of pulling the latch on the hinge, but we found the latch to be rather stiff to operate.
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The experimental drugs latch on to the sense strand of RNA, a messenger form of DNA, thereby blocking the RNA from producing proteins that cause disease.
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