Directions: There are 20 blanks in the following passage. For each blank there are four choices marked A, B, C and D. Choose the ONE that best fits into the passage.

Scientists are learning more about our (41) _______for sleep. Most people sleep (42) _______eight hours each night. (43) _______ people sleep more than (44) _______and others sleep as (45) _______ as two or three hours each night. (46) _______do not know exactly (47) _______some people sleep more than others. Dr. Ernest Hartman has an idea about this. He believes the (48) _______of sleep depends on how a person attacks problems. He said people who need only a few (49) _______sleep usually are people who have much energy and make good use (50) _______ time to get their work (51) _______quickly. (52) _______he said many people who sleep longer than normal do creative work and seem to need (53) _______ dreaming time to find (54) _______to emotional problems. Some scientists agree with this idea and others dispute.

To determine the (55) _______of the lack of sleep, scientists have put subjects (56) _______a set of psychological and performance tests (57) _______them, for instance, (58) _______columns of numbers of recall a passage read to them only minutes earlier, “We’ve found that if you’re in sleep deficit (缺乏), performance suffers,” says Dr. David. “Short-term memory is (59) _______ , as are abilities to (60) _______ decisions and to concentrate.”

(       )41. A. request       B. need                 C. want                      D. fancy

(       )42. A. for              B. at                    C. in                          D. since

(       )43. A. Other          B. The other         C. Some                    D. Many

(       )44. A. that             B. it                     C. the hour                D. the time

(       )45. A. much          B. longer              C. heavily                  D. few

(       )46. A. People        B. Sleeper            C. Scientists               D. They

(       )47. A. why            B. when               C. that                        D. how

(       )48. A. amount       B. count               C. period                    D. stage

(       )49. A. hours          B. hour                C. hour’s                 D. hours’

(       )50. A. of               B. with                 C. on                         D. in

(       )51. A. to be done   B. to do               C. done                      D. do

(       )52. A. And            B. While               C. Thus                      D. But

(       )53. A. extra           B. uncommon       C. extraordinary          D. peculiar

(       )54. A. response     B. solution           C. answer                  D. reaction

(       )55. A. conclusion   B. continue           C. contradiction   D. consequences

(       )56. A. Through      B. out of               C. into                       D. from

(       )57. A. required      B. requiring           C. require                  D.having required

(       )58. A. adding        B. add                 C. in adding               D. to add

(       )59. A. enforce      B. reduced           C. weakened              D. strengthened

(       )60. A. make          B. do                   C. perform         D. conduct