Question 16: So far, he ..................... five stories for children.

          A. writes                                           B. is writing

          C. has written                                   D. has writing

Question 17: If I had enough money, I ................. abroad to improve my English.

          A. will go                                          B. would go

          C. should go                                      D. should have go to

Question 18: Too much carbon dioxide in the atmosphere causes global …………….

A. warm

B. warming

C. warmly

D. warmth

Question 19:  Many fish in my lake have died because of the ………… water

A. pollute             B. pollution                   C. polluted           D. polluting

Question 20:  My teacher always  give us a clear ………..

A. explain            B. explained                   C. explanatory     D. explanation

Question 21:  By the time we got to the cinema, the film …………………...          

A. started                B. starting                       C. starts                   D. had started
 nếu có thể xin cả cách làm ( vì sao làm như vậy nhé )