The popular notion that older people need less sleep than younger adults is a myth, scientists said yesterday.

　　While elderly people 47.tend to sleep for fewer hours than they did when they were younger, this has a 48.negative effect on their brain's performance and they would benefit from getting more, according to research.

　　Sean Drummond, a psychiatrist at the University of California, San Diego, said that older people are more likely to suffer from broken sleep, while younger people are better at sleeping 49.efficiently straight through the night.

　　More sleep in old age, however, is 50.associated with better health, and most older people would feel better and more 51.alert if they slept for longer periods, he said.

　　"The ability to sleep in one chunk overnight goes down as we age but the amount of sleep we need to 52.function well does not change," Dr Drummond told the American Association for the Advancement of Science conference in San Diego.

　　"It's 53.definitely a myth that older people need less sleep. The more healthy an older adult is, the more they sleep like they did when they were 54.younger. Our data suggests that older adults would benefit from 55.continuing to get as much sleep as they did in their 30s. That's 56.different from person to person, but the amount of sleep we had at 35 is probably the same amount we need at 75."

　　47. N 空前有to填動詞

　　48. L 空前冠詞空后n.填a.

　　49. H 空后a.填ad.

　　50. B be associated with 常用詞組

　　51. A 空前more填a.

　　52. J 空前to填動詞

　　53. F 所在句完整 填ad.加強語氣

　　54. O 空前be動詞缺表語填a.

　　55. E 空前介詞, 空后介詞+賓語, 填動名詞

　　56. G 缺表語填a.