1.Hurry up!The play __________ for ten minutes .
A.has begun B.had begun
C.has been on D.began
2. -______ you ______anywhere before?
-Yes, but I can't remember where I______
A. Did; surf; surfed B. Have; surfed; surfed
C. Did; surf; have surfed D. Have; surfed; have surfed
3.The number of the students in our school _______ 1200.
A is added up to B has been added up to
C adds up to D have added up to
4.Harry Potter is a very nice film .I_______ it twice .
A. will see B. have seen C. saw D.see
解析：现在完成时还与once(一次)，twice(两次)，three times(三次)，several times(几次)等表示重复次数的词语连用。故应选B。
5.These kinds of shoes ______ well.
A were not sold B won't be sold C are not sold D don't sell
6.The first use of atomic weapons was in 1945, and their power ______ increased enormously ever since.
A. is B. was C. has been D. had been
解析：因为ever since的意思是“从那时(1945年)起一直到现在”，表示从过去某一时刻起一直延续到现在的动作或状态，要用现在完成时，现在完成时由“have /has+过去分词”构成，所以选C。
7.Years ago we didn’t know this, but recent science ______ that people who don’t sleep well soon get ill.
A. showed B. has shown C. will show D. is showing