Question

请问第6题为什么选A

Answer 1

首先，the number of 要用is，a number of 才用are
其次，是提问你有多少，这里what就是修饰the number of 的，如果要用how many，后面就不能有the number of
望采纳，谢谢!o(>ω<)o

Answer 2

因为句子里面有number.
如果句子问的是 ‘How many’ students are there in your school? 这里面没有用到number这个词就能用How many.
然而 句子里面有number的话 就要用what is. 例句: How many apples are there in your bag. What is the number of apple in your bag.