【C18】
A．in that
B．despite
C．therefore
D．if

判断题重测信度也叫稳定性系数，是估计测验跨时间的一致性的指标。用同一种测验对同一组被试先后施测两次，被试两次测验分数间的相关系数即为重测信度。()

单项选择题有一台六极三相绕线式异步电动机，在f=50Hz的电源上带额定负载运行，其转差率为0.02，电动机的同步转速为( )。 A.900r min B.1200r min C.1000r min D.1400r min

未分类题The average British people get six-and-a-half hours sleep a night, according to the Sleep Council. It has been known for some time that the amount of sleep people get has,【C1】______declined over the years. But【C2】______the average amount of sleep we are getting has fallen, rates of obesity and diabetes have soared. Could the two be connected? We wanted to see what the【C3】______would be of increasing average sleep by just one hour. So we asked seven volunteers, who【C4】______sleep anywhere between six and nine hours, to be【C5】______at the University of Surreys Sleep Research Centre. The volunteers were randomly【C6】______to two groups. One group was asked to sleep for six-and-a-half hours a night, the other got seven-and-a-half hours. After a week the researchers took blood tests and the volunteers were asked to switch sleep【C7】______. The group that had been sleeping six-and-a-half hours got an【C8】______hour, the other group slept an hour less. Computer tests designed to measure brain wave activity【C9】______that most of them struggled with mental agility tasks when they had less sleep, but the most interesting results came from the blood tests that were【C10】______. Dr Simon Archer and his team at Surrey University were【C11】______interested in looking at the genes that were switched on or off in our volunteers【C12】______changes in the amount that we had made them sleep. 'We found that【C13】______there were around 500 genes that were affected,' Archer【C14】______. 'Some which were going up, and some which were going down.' What they discovered is that when the volunteers【C15】______back from seven-and-a-half to six-and-a-half hours sleep a night, genes that are【C16】______with processes like immune response and response to stress became more【C17】______The team also saw increase in the activity of genes related to diabetes and risk of cancer. The【C18】______happened when the volunteers added an hour of sleep. So the clear【C19】______from this experiment was that if you are getting less than seven hours sleep a night and can alter your sleep habits, even one hour more, it could make you【C20】______.【C1】A．by chanceB．on averageC．at lengthD．for good

未分类题【C3】A．hang .B．crashC．landD．move

未分类题When Neil Armstrong and Buzz Aldrin returned from the moon, their cargo included nearly fifty pounds of rock and soil, which were packed in an aluminum box with seals designed to maintain the lunar surfaces low-pressure environment. But back at Johnson Space Center, in Houston, scientists discovered that the seals had been【C1】______—by moon dust. Lunar dust is fine, like a powder,【C2】______it cuts like glass. Its formed when shooting stars【C3】______on the moons surface, heating its rocks and dirt and reducing them to fine particles. Since theres no wind or water to smooth【C4】______edges, the tiny grains are sharp and uneven, and【C5】______nearly everything. 'The intruding【C6】______of lunar dust represents a more challenging engineering design issue, as well as a【C7】______issue for settlers, than does radiation,' wrote Harrison Schmitt, an Apollo 17 astronaut, in his 2006 book, 'Return to the Moon.' The dust damaged space-suits and ate away layers of moon boots. Over the【C8】______of six Apollo missions, not one rock box【C9】______its vacuum seal. Dust followed the astronauts back into their ships, too. According to Schmitt, it smelled like gunpowder and made breathing【C10】______. No one knows precisely what the extremely small particles do to human lungs. The dust not only【C11】______the moons surface, but floats up to sixty miles【C12】______it—as an outer part of its atmosphere, where particles【C13】______the moon by gravity, but are so thin that they【C14】______collide. In the nineteen-sixties, Surveyor probes filmed a glowing cloud floating just above the lunar surface during sunrise. Later, Apollo 17 astronaut Gene Cernan, while orbiting the moon, recorded a【C15】______phenomenon at the sharp line where lunar day meets night. Cernan【C16】______a series of pictures illustrating the changing【C17】______; streams of particles popped【C18】______the ground and hovered, and the resulting cloud came into sharper focus as the astronauts orbiter approached daylight. Since theres no wind to form. and【C19】______the clouds, their origin is something of a mystery. Its【C20】______that theyre made of dust, but no one fully understands how or why they do their thing.【C1】A．destroyedB．stainedC．changedD．consolidated