单句改错,下列各句中均有一处错误,请指出并改正(帮帮忙吧)Could you tell me which gate they have to go?其中Could、tell、 which、to go中有一处错误

问题描述:

单句改错,下列各句中均有一处错误,请指出并改正(帮帮忙吧)
Could you tell me which gate they have to go?
其中Could、tell、 which、to go中有一处错误

have
应该是had.虚拟语气

to go to
这不是虚拟语气啊,只是一般的询问句