来源：学生作业帮 编辑：神马作文网作业帮 分类：英语作业 时间：2024/09/23 19:28:14
关于happen的选择题
（ ）选哪个?权威点 ,说明理由!（）Did you see the traffic accident yesterday?Yes,I saw it_____when I_____past the school gate.A.happen；walk B.happen；was walking C.happened；walking D.happening；have walked
C walk 是延续性动词,而且前面又是WHEN,所以walk加ing.
麻烦采纳,谢谢!
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