第四句话写的不对，所以不做解答。否定句：There isn't a pen.There aren't two brothers.There isn't a post office.There isn't a school.一般疑问句都是把be动词(is,are)提前，回答时如果要肯定回答就是Yes, there + 问句首词，如果否定回答就是No, there + 问句首词 + not：--- Is there a pen?
--- Yes, there is.或No, there isn't.
1. There is a pen.There isn't a pen.Is there a pen?2.There are two brothers.There aren't two brothers.Are theretwo brothers?3.There is a post office.There isn't a
1. There is a pen.There isn't a pen.Is there a pen?2.There are two brothers.There aren't two brothers.Are theretwo brothers?3.There is a post office.There isn't a
