1.5 1 4 2 3
2.Collecting model planes
They will be much lager ang safer
Much lower
No,it won't
Yes,he is
3.were
doing
were rowing
were fishing
Was
taking
was
were listening
wasn't
was running
4.did you used to do
What did they used to do
He used to fly kites
Yes,we did
5.How
What
What
How
6.the tallest
cleaner
more beautiful
buler buler
better
7.isn't it
don't you
No,i don't
are there
there aren't
isn't it
8.play computer games reading
the most interesting
Because there are many wonderful things in books
9.(1)In 2001
(2)略
(3)Changes in beijing
(4)略
10.A landed
afford
power
B It's about a child who becomes friends with an alien dog
CJ7 is cute and helpful