The popular notion that older people need less sleep than younger adults is a myth, scientists said yesterday.
While elderly people __1__ to sleep for fewer hours than they did when they were younger, this has a(n) __2__ effect on their brain's performance and they would benefit from getting more, according to research.

Sean Drummond, a. psychiatrist (心理醫(yī)生) at the University of California, San Diego, said older people are more likely to suffer from broken sleep, while younger people are better at sleeping __3__ straight through the night.
More sleep in old age, however, is __4__ with better health, and most older people would feel better and more __5__ if they slept for longer periods, he said.

"The ability to sleep in one chunk (整塊時間) overnight goes down as we age but the amount of sleep we need to __6__ well does not change," Dr Drummond told the American Association for the Advancement of Science conference in San Diego.
"It's __7__ 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 __8__. Our data suggests that older adults would benefit from __9__ to get as much sleep as they did in their 30s. That's __10__ from person to person, but the amount of sleep we had at 35 is probably the same amount as we need at 75."

[A] alert
[B] associated
[C] attracting
[D] cling
[E] continuing
[F] definitely
[G] different
[H] efficiently
[I] formally
[J] function
[K] mixed
[L] negative
[M] sufficient
[N] tend
[O] younger

答案解析：

文章大意：本文主要講述的是關于老年人睡眠的問題：是否老年人與年輕人相比只需要較少的睡眠時間？

1. N tend?tend to 固定搭配；表示"傾向于；"符合句意；

2. L negative?空格后是effect， 前面是a(n)， 由此可見，該處需要填入一個形容詞；題目給出的形容詞有negative, sufficient, younger；根據前后語意，填入negative最為恰當，表示"少的睡眠時間對大腦的活動有負面的影響。"

3. H efficiently?根據推測，該處應該填入一個副詞，題目給出的副詞有efficiently, definitely, formally；前面提到，老年人在睡覺的時候更容易被打斷，而后面用while提出一個對比的概念，年輕人相比起來能獲得更_______ 的睡眠；綜合起來，選用efficiently（最有效率的）最為準確。

4. B associated?be associated with 固定搭配；表示"與…聯系在一起"；本句話表示"更多的睡眠通常都與健康度聯系在一起"；

5. A alert?先看整句話的含義，"如果他們能睡更長的時間，他們的感覺應該會更好以及…"那么，該處應該填入一個褒義詞，選擇alert比較恰當，表示"更加警覺，機靈"；

6. J function?根據判斷，此處應該填入一個動詞，剩下的動詞有cling, function；整句話的意思是"當我們上了年紀的時候，我們一覺睡到天亮的能力下降了，但是，我們需要…的睡眠量并沒有改變；"空格后的單詞是 well， cling 在這里并不合適，一般與to連用；選用function 最為適合；

7. F definitely?作者在首段已經提出這個觀點是一個myth，那么顯而易見最后一段中出現的myth是作為一種強調手段，應填入definitely；

8. O younger?空格的前面是 when they were…， "當他們年輕的時候"；應填入younger；

9. E continuing?本句的意思是"我們的數據顯示老年人將從…獲益；"空格的后面是"得到和他們在三十多歲的時候能得到的睡眠一樣多"；根據上下文意思，該處應填入"continuing"；

10. G different?different from 固定搭配；表示"和…不同"。