Question

but some people have carried around an unusual peble for weeks before finding out that they had got

a diamond。before是什么意思，before后面的是做目的状语吗

Answer 1

翻译：而有的人数周后才发现带在身边的不寻常的鹅卵石原来是一颗金刚石。
a diamond是“金刚石”的意思，before是“在。。。。。。之前”的意思。before引导的是时间状语从句，表示主句动作发生在从句动作之前。but some people have carried around an unusual peble for weeks 是主句，当主句用将来时，从句before finding out that they had got总是用现在时；从句用过去时，则主句多用过去完成时，以此来体现动作发生的先后顺序。