“How many days are there in a week?”这句话为什么要加“are there”?

还原成陈述句,there are 7 days in a week然后,你对7 进行画线部分提问,就得到此句规则是：首先确定特殊疑问词,是how many days,然后,原句的there are ,的are 提前,就得到How many days are there in a week如果还有...