Find a mistake and correct it

IV. Find a mistake and correct it
11. How many classes is there in your school?
A B C D
12. Nam studys the past and present events in Vietnam and around the world.
A B C D
13. There are a banana and five oranges on the table.
A B C D
14. Linh has a beautiful girl with blonde hair and a fit body.
A B C D
15. Turn left, you can see that the post office is opposite of my house.
A B C D