题目内容：

A group of frogs were jumping through the woods (when) two of them fell into a deep hole
为什么不用Until

优质解答

用when是指,当一群青蛙穿过树林时,两只青蛙掉进了一个深洞.
用until是指,知道两只青蛙掉进一个深洞,一群青蛙才穿过树林.