How long could divers stay underwater in Halley’s bell?
A.Just a few seconds
B.Only a few minutes
C.For days on end
D.For hours at a time

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
This class,_____is a prerequisite for microbiology, is so difficult that I would rather drop it.
A.that
B.when
C.where
D.which

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
Why not ________ the meeting until Thursday morning?
A.postpone
B.postponing
C.you postpone
D.do you postpone

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
If some endangered species ______ in zoos, it would help to ensure their future survival.
A.will be kept
B.are kept
C.had been kept
D.were kept

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
Ann has a lot of books, she has never read.
A.most of that
B.most of these
C.most of which
D.which most of them

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
By the end of this year, Nam _______ English for 7 years , but he will still need more training and experience before he masters the language.
A.will have been studying
B.has been studying
C.will be studying
D.has studied

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
She has two brothers, ___ _ are engineers.
A.whom both
B.both who
C.both of whom
D.both whom

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
Linda refused ______ in the musical performance because she was sick.
A.to participate
B.participate
C.participating
D.to participating

The subject of the preceding passage was most likely Halley’s
A.childhood
B.work as an astronomer
C.invention of the diving bell
D.many different interests

Halley’s bell was better than its predecessors because it ________ .
A.was bigger
B.provided more air
C.weighed less
D.could rise more quickly