用are there开头来问，答语中要出现there are，Is there 开头的问句，答句中要出现there is，例如Are there any students in the classroom，Yes ，There are，Is there a river in front of the house，No there isn't，
二者答语分为肯定情况和否定情况。
1、肯定时：are/is there的答语是Yes, there are.
2、否定时：二者的答语分别是No, there aren't/isn't.
