In our lives, we have to make many decisions. Some people say that we should think about t
第1题
members of the land community have no economic value. Yet these creatures are members of the biotic community. If its stability depends on its integrity, they are entitled to continuance. When one of these non-economic categories is threatened, and, if we happen to love it, we invent excuses to give it economic importance. At the beginning of century, songbirds were supposed to be disappearing. Scientists jumped to the rescue with some distinctly shaky evidence to the effect that insects would eat us up if birds failed to control them. The evidence had to be economic in order to be valid. It is painful to read these roundabout accounts today. We have no land ethic yet, but we have at least drawn nearer the point of admitting that birds should continue as a matter of intrinsic right, regardless of the presence or absence of economic advantage to us.
第2题
lants, where exists a great reluctance 【M1】______ to accept viruses as been of importance in human cancer. Basic 【M2】______ biological phenomena generally does not differ strikingly as 【M3】______ one goes from one species to other. It should be recognized that 【M4】______ cancer is a biological problem and not a problem that is unique for man. Cancer originates when a normal cell suddenly becomes a cancer cell which multiplies widely and with apparent restraint. 【M5】______ Cancer cells originate in many different kinds of cell, but the cancer cell usually continues to carry certain traits of the cell of origin. The transformation of a normal cell to a cancer cell may 【M6】______ have more than one kind of cause, but theres good reason to consider the relationships exist between viruses and cancer. Since theres no evidence which human cancer, as generally 【M7】______ experienced, is infectious, many person believe that because 【M8】______ viruses are infectious agents, they can possibly be of important in 【M9】______ human cancer. Furthermore, viruses and examples are known in which a virus never kills its host can mutate to form. a new strain 【M10】______ of virus that always kills its host. It does not seem unreasonable to assume that an innocuous latent virus might mutate to form. a strain that causes cancer.
【M1】
第3题
Which of the following languages does NOT belong to the Sino-Tibetan family?
A.Chinese.
B.Thai.
C.Burmese.
D.Arabic.
第4题
d more
A.rational.
B.humorous.
C.optimistic.
D.pessimistic.
第5题
y, the very prototype of the empire builder or the pioneer colonist.
A.Tom Jones
B.Gulliver
C.Moll Flanders
D.Robinson Crusoe
第6题
In Australia, April 25 is known as
A.Australia Day.
B.Anzac Day.
C.Independent Day.
D.ANZUS.
第7题
The two newest states which joined the United States of America are
A.Alaska and Florida.
B.Hawaii and Oregon.
C.Alaska and Hawaii.
D.California and New Mexico.
第8题
The most typical English sport, having been in existence since the 16th century, is
A.rugby.
B.soccer.
C.cricket.
D.boxing.
第9题
Today, the City of London is the business center of London where you can find
A.big supermarkets.
B.theaters and cinemas.
C.large financial organizations.
D.restaurants and cafes.
第10题
Which of the following does the author probably agree about the programs effect?
A.It has succeeded in boosting the nation"s economy.
B.It has benefited the American automakers in some ways.
C.It has lowered the fuel consumption in America.
D.It has attracted more overseas consumers into America market.
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