解方程 (每小题5分,共10分)【小题1】(1) 【小题2】 (2) 答案:【小题1】(1)x=1,说明:去括号正确得1分,移项合并同类项正确再得2分,结果正确再得2分。【小题2】(2)x=,说明:去分母正确得2分,化简1分,结果2分。解析:略Younger adults who get
either little sleep or a lot of it may see a greater expansion in their
waistlines(腰围)over time, a study published
suggests. Researchers found that among black and Hispanic adults younger than
40, those who typically slept for five hours or less each night had a greater
accumulation of belly fat over the next five years, versus(相比于)
those who averaged six or seven hours. Those who slept eight hours or more in
bed each night also showed a bigger fat gain - but it was less obvious than
that seen in "short sleepers."
The study, reported in
the Journal Sleep, does not prove that too little or too much sleep directly
leads to excess fat gain. But the findings support and extend those of other
studies linking sleep duration - particularly a lack of sleep - to weight gain
and even to higher risks of diabetes(糖尿病) and heart disease.
Among participants younger than 40, the study found, those who said they slept
for five hours or less each night gained more belly fat than those who averaged
six or seven hours of sleep. On average, short sleepers showed a 32 percent
gain in visceral(内脏的)fat, versus a 13
percent gain among those who slept six or seven hours per night, and a 22
percent increase among men and women who got at least eight hours of sleep each
night. A similar pattern was seen with superficial abdominal(腹部)fat.
The
findings, according to lead researcher Dr. Kristen G. Hairston, support the
belief that sleep habits affect weight and health in general. "Sleep is an
important part of your overall health - not just in whether you're tired during
the day," she said.
There may be indirect
effects; people who get too little sleep may be too tired during the day to
exercise, while those who spend a lot of time in bed may spend less time being
active, relative to people who sleep fewer hours. Research also suggests that
sleep loss alters people's levels of appetite-regulating hormones(荷尔蒙)-
which could, in theory, cause them to overeat. Depression, which often affects
people's sleep and has been linked to weight gain, could also be a factor,
Hairston noted.
1.Who may have the
higher risk of being fat over the next five years?
A. Jack, a Hispanic
man, aged 35, sleeps for 3 hours every night.
B. Candy, a black
woman, aged 41, sleeps for about 5 hours every night.
C. Bob, an American,
aged 50, sleeps for more than 12 hours every day.
D. John, a student in
Africa, sleeps for more than 6 hours every week.
2.What does the study,
reported in the Journal Sleep find?
A. Too little or too
much sleep directly gives rise to the fat gain.
B. People are subject
to heart disease due to the lack of sleep.
C. It is admitted that
sleep plays an important part in our health.
D. Researchers find a
longer sleep time is better for our health.
3.What does the lead
researcher Dr. Kristen G. Hairston agree with?
A. People should do
some exercise in their daily life.
B. There is a close
link between sleep habits and health.
C. More nutrition is
greatly needed when we lack sleep.
D. More and more
people tend to sleep less than before.
4.What can we infer
from the passage?
A. Younger adults
getting little or much sleep may become fat.
B. We are supposed to
do exercise as much as possible to keep fit.
C. We should keep a
good sleep habit to improve our health.
D. We have to spare no
efforts to drive depression away.
5.What’s the best
title of the passage?
A. Sleep Habits Linked
to Fat Gain in Younger Adults.
B. Doing Exercise Is
the Best Way to Keep Fit.
C. Our Waistlines Can
Be Driven Away Right Now.
D. Diabetes No Longer
bother all of Young People.