It can he concluded from the passage that one should sleep as many hours as necessary to ______.
A. improve one's memory dramatically
B. be considered dynamic by other people
C. maintain one's daily schedule
D. feel energetic and perform. adequately
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The underlined word "subjects"(Line 1, Para. 4) refers to ______.
A. the performance tests used in the study of sleep deficit
B. special branches of knowledge that are being studied
C. people whose behavior. or reactions are being studied
D. the psychological consequences of sleep deficit
What is the author going to state in the next paragraph？
A. There have been attempts to start a professional soccer organization in the US.
B. in the 12th century soccer games in Britain often involved whole towns.
C. Professional soccer grew quickly in Europe.
D. Experts believed that the United States would win.
After the use of the laser beam, surgeons can perform. operation which ______.
A. leave their patients with negative effects
B. can treat duly human eye diseases
C. do little damage to their patients
D. make their patients need a long time to recover
Which people are usually not allowed to use the stacks？
A. Library employees.
B. Graduate students.
C. Undergraduate students.
D. Professors.
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