11. Mathematics as well as physics always _ _me a lot of headaches.

　　A. has caused B. are causing C. cause D. causes

　　12. A number of tourists __ received in Grand Hotel.

　　A. was B. is C. has D. are

　　13. The captain is the only one of the players of the team_ _ practice regularly.

　　A. have attended B. who have attended C. who has attended D. who attended

　　14. Two hours _ _ the limit of this rest.

　　A. are B. has been C. have been D. is

　　15. A red rose, together with a letter, _ _ left on the table.

　　A. are B. was C. were D. are being

　　16. Each of the people coming to the party _ _ bringing a present.

　　A. are B. is C, has D. have

　　17. Neither John's family nor his relative _ _ the special banquet.

　　A. attends B. attend C. are attending D. attended

　　18. Although the first chapter of the book appears easy; the rest_ _rather difficult.

　　A. is B. was C. are D. were

　　19. The greater part of your mistakes _ _ through carelessness.

　　A. were making B. will make C. has been made D. were made

　　20. Neither his knowledge nor his experience as an engineer_ _ him for his job.

　　A. have qualified B. are qualifying C. qualify D. qualifies

　　DDCDB BDCDD