Which of the following tells us how caffeine affects sleep？
A. Caffeine blocks production of the enzyme that stops melatonin production.
B. Caffeine interrupts the flow of sleep hormone.
Caffeine halves the body's levels of sleep hormone.
D. Caffeine stays in the body for many hours.
查看答案
What does paragraph 3 mainly discuss？
A. Different effects of caffeinated coffee and decal on sleep.
B. Different findings of Lotan Shilo and a team about caffeine.
C. The fact that the subjects slept 415 minutes per night after drinking decaf.
D. The evidence that the subjects took half an hour to fall asleep.
The 1, 031 adults were interviewed______.
A. on a dally basis for 8 days
B. during one of eight days
C. all by Grzywacz
D. in groups
The author of this passage probably agrees that______.
A. coffee lovers sleep less than those who do not drink coffee
B. we should not drink coffee after supper
C. people sleep more soundly at midnight than at 3 a.m.
D. if we feel sleepy at night, we should go to bed immediately
下列选项中对民事法律关系的表述正确的是：A．哥伦布到无人岛上后，通过劳动逐渐积攒起各种生产、生下列选项中对民事法律关系的表述正确的是：
A. 哥伦布到无人岛上后，通过劳动逐渐积攒起各种生产、生活物资，他在无人岛上主要形成以所有权为主的法律关系
B. 甲男和乙女同居期间，两人约定不因怀孕而产生婚姻问题，后乙怀孕要求与甲结婚，并坚决要求生下孩子，则乙侵犯了甲的生育权，构成违约和侵权的竞合
C. A市税务局某局长甲在职务范围内，以税务局的名义向该市B银行贷款300万元，二者之间形成民事法律关系
D. 甲发现乙和丙都有其需要的商品，就先跟丙接触、商谈此事。丙通知甲在下午两点前将为甲保留商品。后甲又约乙13:00会谈，乙快14:00才赴约，且当甲提出此事，即需要购买乙的商品时，乙称早已卖出，导致甲丧失了与丙订约的机会，甲和乙之间成立民事法律关系
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