牛津译林 8BUnit2 知识点汇总8B Unit21.I've been there be fore. 我此前去过那里。①before 副词“此前”。常与目前完毕时连用，也可与一般过去时连用。He has never seen such a huge stone before.他此前从未见过这样大的石头。②before 介词或...

时间:2025-06-04 07:10栏目:高等教育