关于天然石材的技术性质，下列说法不正确的是（）。

After how many minutes does an average person repeat the sleep cycle？

A．8 to 15 minutes.

B．30 minutes.

C．40 to 60 minutes.

D．80 minutes.

conjectural (猜想), rendering conclusive answers to this question impossible, much evidence has been gathered on how much sleep people do in fact obtain. Perhaps the most important conclusion to be【32】from this evidence is【33】there is great variability among individuals in total sleep time. For adults,【34】between six and nine hours of sleep as a nightly average is not unusual, and 7.5 hours probably best expresses the norm. Such norms, of course, forms inevitably vary with the criteria of sleep employed, The most【35】and reliable figures on sleep time, including those cited here, come from studies in sleep laboratories, where EEG criteria are employed.

【36】consistently has been associated with the varying amount, quality, and pattern of electrophysiologically defined sleep. The newborn infant may spend an average of about 16 hours of each 24-hour period in sleep,【37】the sleep time drops sharply; by two years of age, it may【38】from nine to 12 hours. Decreases to approximately six hours have been observed among the elderly.

【39】will be discussed from below, EEG sleep studies have indicated that sleep can be considered to consist of several different stages. Developmental changes in the relative proportion of sleep time【40】in these sleep stages are as striking as age-related changes in total sleep time.

(31)

A．As

B．Despite

C．While

D．Whether

A．Flies need less sleep than humans.

B．Humans need a similar amount of sleep with flies.

C．The amount of human sleep is determined by certain gene.

D．Flies can determine how much sleep they need.

—

— The round-trip air fare for a person is only $188.

A、What is the exact air fare？

B、How much does the airplane cost？

C、How much does the trip cost？

conjectural(猜想), rendering conclusive answers to this question impossible, much evidence has been gathered on how much sleep people do in fact obtain. Perhaps the most important conclusion to be【B2】from this evidence is【B3】there is great variability among individuals in total sleep time. For adults,【B4】between six and nine hours of sleep as a nightly average is not unusual, and 7.5 hours probably best expresses the norm. Such norms, of course, forms inevitably vary with the criteria of sleep employed. The most【B5】and reliable figures on sleep time, including those cited here, come from studies in sleep laboratories, where EEG criteria are employed.

【B6】consistently has been associated with the varying amount, quality, and pattern of electrophysiologically defined sleep. The newborn infant may spend an average of about 16 hours of each 24-hour period in sleep,【B7】the sleep time drops sharply; by two years of age, it may【B8】from nine to 12 hours. Decreases to approximately six hours have been observed among the elderly.

【B9】will be discussed from below, EEG sleep studies have indicated that sleep can be considered to consist of several different stages. Developmental changes in the relative proportion of sleep time【B10】in these sleep stages are as striking as age-related changes in total sleep time.

【B1】

A．As

B．Despite

C．While

D．Whether

"It's 53.____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 54.____. Our data suggests that older adults would benefit from 55 to get as much sleep as they did in their 30s. That's 56.____from person to person, but the amount of sleep we had at 35 is probably the same amount we need at 75."

conjectural(猜想), rendering conclusive answers to this question impossible, much evidence has been gathered on how much sleep people do in fact obtain. Perhaps the most important conclusion to be【B2】from this evidence is【B3】there is great variability among individuals in total sleep time. For adults,【B4】between six and nine hours of sleep as a nightly average is not unusual, and 7.5 hours probably best expresses the norm. Such norms, of course, forms inevitably vary with the criteria of sleep employed. The most【B5】and reliable figures on sleep time, including those cited here, come from studies in sleep laboratories, where EEO criteria are employed.

【B6】consistently has been associated with the varying amount, quality, and pattern of electrophysiologically defined sleep. The newborn infant may spend an average of about 16 hours of each 24-hour period in sleep,【B7】the sleep time drops sharply; by two years of age, it may【B8】from nine to 12 hours. Decreases to approximately six hours have been observed among the elderly.

【B9】will be discussed from below, EEO sleep studies have indicated that sleep can be considered to consist of several different stages. Developmental changes in the relative proportion of sleep time【B10】in these sleep stages are as striking as age-related changes in total sleep time.

【B1】

A．As

B．Despite

C．While

D．Whether

If a person is considered to be a genius, what scores does he need to get in an IQ test？

A．Lower than 90.

B．Between 90 and 110.

C．Between 110 and 140.

D．As much as 140 or more.

A．need

B．use

C．cost

D．take