关于劳动力的需求计划表的表格的形式,说法正确的是:()。
A. 国家及行业无统一限制,各企业可根据自身需要来制定
B. 按国家统一格式
C. 按行业统一格式
D. 既可按国家统一格式也可按行业统一格式
查看答案
材料题请点击右侧查看材料问题 查看材料
A. difficult
B. easy
C. typical
D. unusual
(49)__________ 查看材料
Another distinction between science and technology has to do with the progress in each.
B. Unlike science, progress in technology must be measured in terms of the human factor.
C. What scientists discover may shock or anger people——as did Darwin"s theory of evolution.
D. Science and technology are different.
E. We are all familiar with the improper use of technology.
F. Science is a method of answering theoretical questions; technology is a method of solving practical problems.
热拌沥青混凝土路面属于()。
A. 高级路面
B. 次高级路面
C. 中级路面
D. 低级路面
Late-Night Drinking
根据内容回答题.
Coffee lovers beware. Having a quick "pick-me-up" cup of coffee late in the day will play havoc with your sleep. As well as being a stimulant, caffeine interrupts the flow of melatonin, the brain hormone that sends people into a sleep.
Melatonin levels normally start to rise about two hours before bedtime. Levels then peak be-
tween 2 a.m. and 4 a. m. , before falling again. "It&39;s the neurohormone that controls our sleep and tells our body when to sleep and when to wake," says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body&39;s levels of this sleep hormone.
Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six vol-
unteers slept less well after a cup of caffeinated coffee than after drinking the same amount of de- caf(脱因咖啡). On average, subjects slept 336 minutes per night after drinking caffeinated cof- fee, compared with 415 minutes after decaf. They also took half an hour to drop off—twice as long as usual--and jigged aroused in bed twice as much.
In the second phase of the experiment, the researchers woke the volunteers every three hours and asked them to give a urine sample, Shilo measured concentrations of a breakdown product of melatonin. The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers. In a paper accepted for publication in Sleep Medicine, the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production.
Because it can take many hours to eliminate caffeine from the body, Ohayon recommends that coffee lovers switch to decal after lunch.
The author mentions" pick-me-up" to indicate that 查看材料
A. decaf is a caffeinated coffee
B. coffee is a stimulant
C. neurohormone can wake us up
D. melatonin levels need to be raised