更多"Enamel, the hardest substance in a "的相关试题:
[单项选择]Enamel,the hardest substance in a human being's body,covers the entire crown of the tooth.（ ）
A. whole
B. inseparable
C. superficial
D. main
[单项选择]Enamel, the hardest substance in a human being's body, covers the entire crown of the tooth.（）
A. whole
B. inseparable
C. superficial
D. main
[单项选择]Scientists and economists believe that human being can never use away all the mineral resources on Earth.（ ）
A. believe
B. can never
C. use away
D. mineral
[单项选择]The longest time a human being can survive without sleep is probably ______ .
A. five days
B. seven days
C. ten days
D. twelve days
[单项选择]
Passage one
Every human being, no matter what he is doing, gives off body heat. The usual problem is how to dispose of it. But the designers of the Johnstown campus of the University of Pittsburgh set themselves the opposite problem of how to collect body heat. They have designed a collection system which utilizes not only body heat, but the heat given off by such objects as light bulbs and refrigerators as well. The system works so well that no conventional fuel is needed to make the campus's six buildings comfortable. Some parts of most modern buildings-theatres and offices as well as classrooms-are more than amply heated by people and lights and sometimes must be air-condition even in winter. The technique of saving heat and redistributing it is called “heat recovery”. A few modem building recover heat but the University’s system is the first to recover heat from some buildings and re-use it in others.
Along the way, Pitt
A. was difficult to collect
B. came in a variety of forms
C. was difficult to get rid of
D. tended to be absorbed by physical objects
[单项选择]Every human being who has ever lived had two parents. Therefore, more people were alive three thousand years ago than are alive now.
The reasoning in the argument is flawed because it
A. overlooks the number of people in each generation during the last three thousand years who left no descendants.
B. disregards possible effects of disasters such as famines and plagues on human history.
C. overestimates the mathematical effect of repeated doublings on population size.
D. fails to take into account that people now alive have overlapping sets of ancestors.
E. (E) fails to consider that accurate estimation of the number of people alive three thousand years ago might be impossible.
[单项选择]The writer thinks human being's leaving the stage can be any of the following but __________.
[单项选择]
Placing a human being behind the wheel of an automobile often has the same curios effect as cutting certain fibres in the brain.
The result in either case is more primitive behaviour. Hostile feelings are apt to be ex pressed in an aggressive way.
The same man who will step aside for a stranger at a doorway will, when behind the wheel, risk an accident trying to beat another motorist through an intersection. The importance of emotional factors in automobile accidents is gaining recognition. Doctors and other scientists have concluded that the highway death toll resembles a disease epidemic and should be investigated as such.
Dr Ross A. McFarland, associate professor of industrial Hygiene at the Harvard University School of Public Health, aid that accidents "now constitute a greater threat to the safety of large segments of the population than diseases do."
Accidents are the leading cause of death between the ages of 1 and 35. About one th
A. shy
B. borderline psychopathic cases
C. criminally insane
D. neurotic
[填空题]
Every human being is fallible; we make mistakes. In America
when a mistake has been made, it is considered fitting for the person{{U}}
(1) {{/U}}to acknowledge his or her error and to apologize to anyone who
has been inconvenienced. Even{{U}} (2) {{/U}}are expected to admit
their mistakes and apologize for them. Trying to{{U}} (3) {{/U}}a
mistake and denying your guilt are considered to be indicative of serious{{U}}
(4) {{/U}}.
If you make a mistake that{{U}} (5)
{{/U}}a group of people, a public apology is considered the best method
for{{U}} (6) {{/U}}. If the mistake was a serious one, or if some
people were inconvenienced more than others, then the{{U}} (7)
{{/U}}should follow the public apology with private ones to{{U}} (8)
{{/U}}.
It is especially important for executives and company
heads to be able to admit their mistakes. Sometimes leaders are afraid that if
they{{U}} (9) {{/U}}, they wi
