1 Tim is at the same age as Hoa. 

             => bỏ at

2. At recess, the students practice to play basketball.

                                                       => playing 

3. Do you know how much a banana cost?

                                                           => costs

4. The tacher says Ba will be a famous artist in one day. 

                                                                    => one day

5. Some boys are playing marble in the school yard at recess. 

                                       => marbles

6. Some students are playing games as blind man’s buff and catch.

                                                     => like

7. Mai learns how to use a computer in her scientific class. 

                                                                      => science

8. I’d love coming to your birthday but I’m much too busy. 

           => to come

9. There are less TV programs for teenagers than there are for adults. 

                => fewer

10. People are living longer so there are more and more many old people 

                                                                                          => bỏ many