Would you please call me up late to make sure_____they will fly to Beijing 横线上用if 还是that?
问题描述：
Would you please call me up late to make sure_____they will fly to Beijing 横线上用if 还是that?
那如果这句话我要用that应该怎么改啊？我怎么知道它是确定还是没有？
答
if