9. As ?____? clear from his manners, he is a teacher.?
A. being
B. is
C. to be
D. been?
10. Great as Newton was, many of his ideas ?____? today and are being modified by the work of scientists of our time.?
A. are to challenge
B. may be challenged?
C. have been challenged
D. are challenging?
11. It is necessary that the students ?____? more excercises to do.?
A. have
B.must have
C. will have
D. can have?
12. The present situation forced us to ?____? this policy.?
A. adapt
B. admit
C. adopt
D. adjust?
13. We can ?____? the two islands with a bridge.?
A. unite
B. connect
C. relate
D. combine?
14. Due to the bad weather the plane was ?____? for two hours.?
A. delayed
B. canceled
C.postponed
D. dismissed?
15. The ?____? populated area was a breeding place forinfectious diseases.?
A. densely
B. sparcely
C. improperly
D. poisonous?
16. Perhaps the customer has ?____? his monthly statement and not paid the bill.?
A. omitted
B. bewildered
C. overlooked
D. escaped?