41.Too much ____ to X-rays can cause skin burns , cancer of other damage to the body.
A)disclosure
B)exhibition
C)contact
D)exposure
42.When confronted with such questions , my mind goes ____, and I can hardly remember my own date of birth.
A)dim
B)blank
C)faint
D)vain
43.More than two hundred years ago the United States ____ form the British Empire and became an independent country.
A)got off
B)pulled down
C)broke away
D)dropped off
44.Care should be taken to decrease the length of time that one is____ loud continuous noise.
A)subjected to
B)filled with
C)associated with
D)attached to
45.Some of the most important concepts in physics their success ____ to these mathematical systems.
A)oblige
B)due
C)contribute
D)attribute
46.I support your decision , but I should also make it clear that I am not going to be ____ to it.
A)connected
B)fastened
C)bound
D)stuck
47.The English language contains a(n)____of words which are comparatively seldom used in ordinary conversation.
A)altitude
B)latitude
C)multitude
D)attitude
48.So forcefully ____ that we were all convinced.
A)he did speak
B)he spoke
C)did he speak
D)that he spoke
49.We shall start at seven if it ____ by that time.
A)will stop raining
B)stops to rain
C)has stopped raining
D)will have stopped to rain
50.____ you may be right, I can’t altogether agree.
A)As
B)While
C)If
D)Since