VERB
松开；解开
If you unfasten something that is closed, tied, or held together, or if you unfasten the thing holding it, you loosen or remove the thing holding it.
例句
When Ted was six we decided that he needed to know how to fasten and unfasten his seat belt...
特德六岁的时候，我们认为他得知道如何系上和解开安全带了。
Reaching down, he unfastened the latch on the gate...
他伸手打开了门闩。