Test Nine Recent studies of the human brain have resulted in some interesting discoveries． Scientists believe that a way to improve the 1of the brain may soon be possible．
Scientists have discovered2the brain can make its own drugs． The brain3 a protein substance which can act directly 4 the brain to change 5of mental activity． Some may change or improve, 6,creativity, intelligence, imagination, and good7．
Chemicals found in the brain 8 messages． In recent years scientists have found chemicals that 9 mood, memory and other 10 of the mind． About 25 have been found11
Today the role of chemicals and 12 protein substance in human behavior13 much interest．Research seems to show that they may help 14 insomnia, pain, and mental illness． They have a great 15 to stimulate the brain to 16 deficiencies． They also improve the 17 of memory and learning already in the brain． They hold the secret 18mood and emotion． Some day 19 may be a chemical way to create a better and more 20 brain．
1．A） case B）fashion C）power D）impact
2．A） that B）what C）whether D）when
3．A） entertains B）restrains C）sustains D）contains
4．A） against B）on C）for D）to
5．A） places B）aspects C）speeds D）behaviors
6．A） as a result B）in the end C）for example D）for this reason
7．A） character B）temper C）spirit D）memory
8．A） obtain B）accept C）carry D）receive
9．A） approach B）affect C）aid D）apply
10．A） happenings B）findings C）dealings D）understandings
11．A） so many B）so much C）so far D）so good
12．A） a B）the C） D）its
13．A） is creating B）are creating C）have created D）was creating
14．A） conceal B）compress C）confine D）control
15．A） courage B）capacity C）authority D）curiosit
16．A） contain B）contest C）conquer D）condemn
17．A） amounts B）quantities C）qualities D）contents
18．A） to B）in C）on D）with
19．A） this B）there C）that D）here
20．A） excessive B）economical C）elaborate D）efficient
Key to Test Nine 1．C 2．A 3．D 4．B 5．B 6．C 7．D 8．C 9．B 10．A
11．C 12．B 13．A 14．D 15．B 16．C 17．C 18．A 19．B 20．D
