There is .in the .造句让造单数和复数（用There are)和不可数的,各3句,我主要是不知道不可数是There is后面的不可数,还是in the什么不可数.给我造出句啊我还想问我写There is a book in schoolbag.用不用加the？

There is a ball in the backpack

1.There is a book in his hand.
There is a pen in the pencil-box.
There is a desk in my room.
注:There is + (a/ an)+ 可数名词单数 + 地点
2.There is some milk in the glass.
There is a piece of bread in the plate.
There is some water in the bottle.
注:there is + 不可数名词 + 地点
3.There are forty desks in my classroom.
There are some books in the desk.
There are some pictures in the classroom.
注:there are + 可数名词复数 + 地点
如果有两个或两个以上的名词,看第一个名词决定用is/ are ( there be 句型的就近原则)
如:There is a book and two pens on the desk.
There are two pens and a book on the desk.