During electrophoresis circulate water or another suitable cooling liquid through the metal plate prevent the temperature from rising above 15℃In atmospheres of high humidity,condensation of moisture may occur on the surface of the layer of medium A if the ventilation of the box and cooling are not adequately controlled.Which of the following should be employed to prevent the temperature from rising above 15℃（）
| Traditionally, the study of history has
had fixed boundaries and focal points—perious, countries, dramatic events, and
great leaders. It has also had clear and firm notions of scholarly procedure:
how one inquires into a historical problem, how one presents and documents one’s
findings, what constitutes admissible and adequate proof. Anyone who has followed recent historical literature, can testify to the revolution that is taking place in historical studies. The currently fashionable subjetcs come directly from the sociology catalog: childhood, work, leisure. The new subjects are accompanied by new methods. Where history once was primarily narrative, it is now entirely analytic. The old questions "What happened" and "How did it happen" have given way to the question "Why did it happen" Prominent among the methods used to answ A. The approach of psychohistorians to historical study is currently popular even though it lacks the rigor and verifiability of traditional historical method. B. Traditional historians can benefit from studying the techniques and findings of psychohistorians. C. Areas of sociological study such as childhood and word are of little interest to traditional historians. D. The psychological assessment of an individual’s behavior and attitudes is more informative than the details of his or her daily life. [单项选择]What is done after a feasibility study
A. Prepare a project charter. B. Create a project plan. C. Create a preliminary project scope statement. D. All of the above. [单项选择]What is the purpose of this study
A. To record social habits B. To analyze anti-social behavior C. To analyze frequency and purposes of social gatherings D. To analyze frequency and purposes of keeping diaries [单项选择]Psychologists study the meaning of color preference because ______.
A. colors may affect the emotional states of the people B. colors may decide the results of our work and study C. color preference can tell you who your friends are D. color preference can help you to see through your enemies [单项选择]Passage One
A recent study indicates that the “short sleepers” had been more or less average in their sleep needs until the men were in their teens. But at about age 15 or so, the men voluntarily began cutting down their nightly sleep time because of pressures from school, work, and other activities. These men tended to view their nightly periods of unconsciousness as bothersome interruptions in their daily routines.
In general, these “short sleepers” appeared ambitious, active, energetic, cheerful, conformist in their opinions, and very sure about their career choices. They often held several jobs at once, or work fullor parttime while going to school. And many of them had a strong urge to appear “normal” or “acceptable” to their friends and associates.
When asked to recall their dreams, the “short sleepers” did poorly. More than this, they seemed to prefer not remembering. In similar fashion, their usual way of dealing with psychological problems was to deny that t
A. are ideally vigorous even under the pressures of life B. often neglect the consequences of inadequate sleep C. do not know how to relax properly D. are more unlikely to run into mental problems 我来回答: 提交
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