Reading passages

49. The main point made by the passage is that the human brain.
A)is much inferior to any known computer 
B)is infinitely more complex and powerful than any computer 
C)is not as complicated and mysterious as has usually been thought 
D)reaches its maximum efficiency at the age of three 
E) has been entirely reproduced in computer form 
50. It is explained in the passage that the efficiency of the computer_______
A)depend on the speed with which the data are collected 
B)will soon make it possible for man to be served by robots 
C)can best be appreciated in the decision-making positions 
D)is the result of its being concentrated on one task at a time 
E) depends on sophisticated electro-mechanical interactions 
51. The author feels that Computers.
A)have contributed immensely to the improvement of living standards 
B)are becoming unaffordable as they get more developed 
C)have been unnecessarily overrated 
D)will be a major force behind all future progress 
E) are capable of doing all the tasks the human brain performs even more efficiently 
Most substances, either artificial or natural, can cause harm to man or the environment. 
Some of these reach the environment in waste streams; however emission limits and 
environmental quality standards can, in some instances, reduce the amounts released. 
However, some other matters cannot be controlled in this way because they are released, 
not in industrial waste streams, but through the use or disposal products which contain 
them. In many cases these substances pose little or no threat if the product containing 
them is used and disposed of properly. The accurate way to deal with them is through 
controls over their supply, use and disposal 
52. 
According to the passage, the threat of some certain substances to the 
environment_________.
A)is for less than that to man 
B)could be reduced by enforcing emission limits and environmental controls 
C)has been unnecessarily over emphasized 
D)has to date been completely ignored 
E) can be eliminated by the use of industrial waste streams 

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