any pictures on the wall. =There are no pictures on the wall.
There is a bike behind the tree. → There isn't a bike behind the tree. =There is no bike behind the tree. 2：变成一般疑问句
There be句型的一般疑问句变化是把be动词调整到句首，再在句尾加上问号即可。但同时要注意：当肯定句中有some时，要将其改为any（否定变化也一样）。
There is some water on Mars. → Is there any water on Mars?
There are some fish in the water. →Are there any fish in the water?
3：特殊疑问句
对主语提问：当主语是人的时候，则用who 引导，当主语是物的时候，则用what 引导。注意：无论原句的主语是单数还是复数，对之提问时一般都用be的单数形式(回答时却要根据实际情况来决定)。如：
There are many things over there. →What's over there? There is a little girl in the room.→Who is in the room? 对地点状语提问：则用where 引导。如：