选词填空

选词填空
The popular notion that older people need less sleep than younger adults is a myth, scientists sai d yesterday.
While elderly people __47__ to sleep for fewer hours than they did when they were younger, this has a(n) __48__ effect on their brain's performance and they would benefit from getting more, a ccording to research.
Sean Drummond, a. psychiatrist (心理医生) at the University of California, San Diego, said older people are more likely to suffer from brok en sleep, while younger people are better at sleeping __49__ straight through the night.
More sleep in old age, however, is __50__ with better health, and most older people would feel b etter and more __51__ if they slept for longer periods, he said.
“The ability to sleep in one chunk (整块时间) overnight goes down as we age but the amount of sleep we need to __52__ well does not ch ange,” Dr Drummond told the American Association for the Advancement of Science conferenc e in San Diego.
“It's __53__ a myth that older people need less sleep. The more healthy an older adult is, the m ore they sleep like they did when they were __54__. Our data suggests that older adults would b enefit from __55__ to get as much sleep as they did in their 30s. That's __56__ from person to pe rson, but the amount of sleep we had at 35 is probably the same amount as we need at 75.”
15选10
47. N tend 48. L negative 49. H efficiently
50. B associated 51. A alert 52. D cling 53. F definitely
54. O younger 55. E continuing 56. G different
Questions 47 to 56 are based on the following passage.
With the world's population estimated to grow from six to nine billion by 2050, researchers. businesses and governments are already dealing with the impact this increase will have on everything from food and water to infrastructure (基础设施) and jobs. Underling all this 47 will be the demand for energy, which is expected to double over the next 40 years.
Finding the resources to meet this demand in a 48 . sustainable way is the cornerstone (基石) of our nation's energy security, and will be one of the major 49 of the 21st century. Alternative forms of energy- bio-fuels, wind and solar, to name a feware 50 being funded and developed, and will play a growing 51 in the world's energy supply. But experts say that even when 52 , alternative energy sources will likely meet only about 30% of the world's energy needs by 2050.
For example, even with 53 investments, such as the $93 million for wind energy development 54 in the American Recovery and Reinvestment Act, important alternative energy sources such as wind and bio-fuels 55 only about 1% of the market today.
Energy and sustainability experts say the answer to our future energy needs will likely come from a lot of 56 both traditional and alternative.
A)stable I)exactly
B)solutions J)consist
C)significant K)comprise
D)role L)competitions
E)progress M)combined
F)marvelous N)challenges
G)included O)certainly
H)growth。