句子开头是there is怎么改为复数形式?

题目

句子开头是there is怎么改为复数形式?
句子开头是there is怎么将其改为复数形式?下面有一些题目,麻烦厉害的朋友帮我的忙
例:There is a pencie on the desk
There are some pencies on the desk
1.There is a watch on the table.
2.There is a knife near that tin.
3.There is a policiman in the kitchen.
4.There is a cup on the table.
5.There is a letter on shelf.
6.There is a peach on the desk.
7.There is a passport on the shelf.
8.There is a fish in the cupboard.
9.There is a tree in the garden.
10.There is a boat on the river
如果回答者能告诉我为什么要这样改那就更好了,简短一点就好!

答案

1.There are some watches on the table.
2.There are some knives near that tin.
3.There are some policimen in the kitchen.
4.There are some cups on the table.
5.There some letters on shelf.
6.There some peaches on the desk.
7.There are some passports on the shelf.
8.There are some fish in the cupboard.
9.There are some trees in the garden.
10.There are some boats on the river