paragraph 1:How useful are trees ?Are there enough trees on
there are not have enough trees on Earth对吗
What are trees useful for?
There are __________young trees on the hill.
there are many trees on the t____.
There are trees on the earth.
how many trees are
How many trees are there on top of the mountain?这里的on top of
There are trees on either side of the river与There are trees
There are many trees on _____side of the street.How beautifu
There are many trees planted
There are many trees on____
How much trees are there in the garden?(改错)