bài 1
1.
It’s not difficult ........ this exercise.
a to do
b doing
c for doing
2.
I think it’s ........ to guess what will happen.
a difficult
b difficulty
c difference
3.
It’s ........ to take a break at least twice a day.
a unimportance
b important
c importance
4.
It’s easy ........ a car.
a drive
b to drive
c driving
5.
It’s happy to ........ her songs.
a listen
b listen to
c do
bài 2

1. It/be/happy/ play/tennis/in/the/summer 
2. It/be/happy/ play/tennis/last summer 
3. It/be/happy/ learn vocabulary/with/ good dictionary.
4. It/be/easier/ me/learn vocabulary/with/ good dictionary.