They go to school on foot（加by bus变为选择疑问句） ___they go to school on foot or bu bus?

Do they go to school on foot or by bus?
希望对你有所帮助 ,有不明白的再问吧补全对话。辛苦你一下。Zhang:Excuse me.___is this blue pen?Is it___.Wang:___me see ,please.Oh,no,it's not mine.My pen is black.I think it's Li's.Li:It is not mine.I think it looks___Zhao's.His pen is blue.Zhang:Zhao,is it yours?Zhao:yes,you're___.Zhang:You___look after it.Zhao:Yes,thanks.Zhang:That's all right.whoseyourslet like right must