They are English girls（改为单数）
She is an English girl
There are five boxes on the desk(five)对括号部分提问
How many boxes are there on the desk?
Are these his new kites?(否定回答）
No,they aren't
Their dog is under the tree(对Their提问）
Whose dog is under the tree?
They are from America(对America提问）
Where are they from?
There are some boats on the lake(对some boats提问）
What are there on the lake?
They are Lily's balls(对 Lily's balls提问）
What are they?
I have dog (改为一般疑问句）
Do you have a dog?
Our school has a garden(写出同义句）
There is a garden in our school
I have four books in my school bag(改为同义句）
There are four books in my school bag
They are my teachers?(对my teachers提问）
Who are they?
Please close the door(改为否定句）
Don't close the door
It is a bus（改为复数形式）
They are buses
is twenty a there and the students teacher in classroom(连词成句）
There is a teacher and twenty students in classroom
希望能够帮到你,欢迎追问~\(^o^)/~