Mark the letter A, B, C, or D on your answer sheet to indicate the BEST ANSWER to each of the following questions  from 11 to 20 (3.25 pts)
 

15. Last night, I ________ the washing up when the lights went out.

        A. did                B. was doing                                   C. am doing        D. doing

16. His lesson is going to be ________ Thursday.

        A. on                             B. in                          C. during        D. at

17.It’s dangerous ________ in this river.

        A. swim               B. you swim                                        C. swimming        D. to swim

18. English ________ in many countries in Asia.

        A. speaks                  B. is spoken                      C. is speaking        D. has spoken