Once again, science supports what your grandmother told you: A good night's sleep helps your body fight a cold.
People who averaged fewer than seven hours of sleep per   1   in the weeks before being exposed to the cold virus were nearly three times  2   likely to get sick as those who  3   eight hours or more, a new study found.
Researchers used frequent telephone  4   to track the sleep  5   of more than 150 men and women aged 21 to 55 over the course of a few weeks. Then they  6   the subjects to the virus, quarantined them for five days and kept  7   of who got sick.
8   sleeping more, sleeping better also seemed to  9   the body fight illness: Patients who fared better on a measure  10   as 'sleep efficiency' - the percentage of time in bed that you're actually sleeping - were also  11   likely to get sick.
The results held  12   even after researchers  13   for variables such as body-mass index, age, sex, smoking and pre-existing antibodies to the  14   .
15   your grandmother, the researchers aren't exactly sure  16   sleeping better makes you less likely to  17   a cold. But they  18    take a stab at the answer: 'Sleep disturbance influences the regulation of proinflammatory cytokines（促炎细胞因子）, histamines, and other symptom mediators that are released in response to infection.' In plain English, maybe tossing and turning when you're  19   with the cold virus  20   to the symptoms that define a cold.
The researchers were based at Carnegie Mellon, the University of Pittsburgh and the University of Virginia, and the study was funded by the National Institutes of Health.
(   ) 1. A. day             B. night                C. week                       D. month
(   ) 2. A. more          B. as                    C. less                         D. same
(   ) 3. A. occurred     B. worked             C. averaged                  D. longed
(   ) 4. A. interviews   B. reports             C. announcements         D. demands
(   ) 5. A. hobbies       B. quality             C. progress                  D. habits
(   ) 6. A. exposed      B. placed              C. protected                 D. prayed
(   ) 7. A. touch          B. check                      C. track                       D. reward
(   ) 8. A. Except               B. Besides             C. Within                     D. Through
(   ) 9. A. benefit               B. guard                C. help                             D. assist
(   ) 10. A. known      B. acted                C. appointed                D. classified
(   ) 11. A. more         B. less                  C. far                          D. totally
(   ) 12. A. ideal         B. false              C. actual                         D. true
(   ) 13. A. adopted     B. adjusted            C. enlarged                  D. employed
(   ) 14. A. bodies       B. cells                 C. virus                       D. medicines
(   ) 15. A. Like          B. As                    C. Against                    D. By
(   ) 16. A. What               B. When                  C. Where                     D. Why
(   ) 17. A. develop     B. form                C. fight                       D. prevent
(   ) 18. A. did           B. often                C. do                           D. never
(   ) 19. A. infected     B. surrounded       C. limited                    D. attached
(   ) 20. A. pulls         B. promotes          C. speeds                     D. contributes