和大家说的一样： 一把钥匙=a key 一串钥匙=a bunch of keys，你也可以说a set of keys，都是一串钥匙。

一串钥匙 a bunch of keys 一把钥匙 a key

"一 串 钥匙 = a bunch of keys "一 把 钥匙" = a key

1. She fished out a bunch of keys from her handbag. 她从提包里掏出一串钥匙来。 2. As he picked up the envelope,a key fell out. 他拾起信封时，一把钥匙掉了出来。

一串钥匙 = Bunch of Keys 一把钥匙 = A Key