我只知道How many ....are there...
例如:原句There are six apples on the tree.(对six提问)
答案:How many apples are there on the tree? 树上有多少苹果?
因为原句中有there are ,所以,问句中也要有,但因为是疑问句,所以用are there. 如果原句是单数,问句还是用复数。
例如:原句There is an apple on the table.(对an提问)
答案:How many apples are there on the table?
参考资料:自己