题目内容
A Biological ClockEvery living thing has what scientists call a biological clock that controls behavior. The bio- logical clock tells______ （51 ）when to form. flowers and when the flowers should open. It tells ______ （52） when to leave the protective cocoons and fly away， and it tells animals and human beings when to eat， sleep and wake.
Events outside the plant and animal ______ （53）the actions of some biological clocks. Scientists recendy found， for example， that a tiny animal changes the color of its fur______（54） the number of hours of daylight. In the short______（55） of winter， its fur becomes white. The fur becomes gray brown in color in the longer hours of daylight in summer，
Inner signals control other biological docks， german scientists found that some kind of internal clock seems to order birds to begin their long migration（56） twice each year. Birds______ （57） flying become restless when it is time for the trip， ______（58）they become calm again when the time of the flight has ended.
Scientists say they are beginning to learn which______ （59） of the brain contain biological clocks. An American researcher， Martin Moorhead， said a small group of cells near the front of the brain ______ （60） to control the timing of some of our actions. These______ （61） tell a person when to______ （62）， when to sleep and when to seek food. Scientists say there probably are other biological clock cells that control other body activities.
Dr. Moorhead is studying ______ （63）our biological clocks affect the way we do our work. For example， most of us have great difficulty if we must often change to different work hours.
______ （64） can take many days for a human body to accept the major change in work hours. Dr. Moorhead said industrial officials should have a better understanding of biological clocks and how they affect workers. He said______ （65） understanding could cut sickness and accidents at work and would help increase a factory"s production.
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{char*name；
int age；
}s[]={"LiHua"，18，"WangXin"，25，"LiuGuo"，21}；
define N(sizeof(s)/sizeof(s[0]))
void f(struct porb a[]，int n)；
main()
{
f(s，N)；
}
void f(struct porb a[]，int n)
{
int i；
for(i=0；i＜n；i++)
printf("%s：d\n"，a[i]．name，a[i]．age)；
}
The British council put the figure of 750 million English language speakers. The only【53】 that the percentage of papers published in English has gone from 65% to 85% in the last 25 years is self-explanatory and only【54】the prevalence of English in all spheres of life. The importance of English skills has been exaggerated to the【55】that it overweighs practically everything in assessing person’s competency.
【56】of controversial information that English dominance will be replaced by Chinese, Arabic or Hindi languages by 2050, which was introduced by a linguist and methodologist David Graddol, a quantity of English language learners is increasing by【57】and bounds.
It is quite reasonable that everybody in the world should be【58】an opportunity to learn English in order to be able to communicate effectively at the global level Though, this is by no【59】always the case that English learning comes easily to people. Many English learners struggle with English to no purpose for years and cannot master it, whatever【60】they exert.
The point is that some people have【61】linguistic abilities, so called a feeling for languages and a way【62】for others is to learn how to learn English effectively. Most of us can succeed【63】dint of our diligence and perseverance. Undoubtedly, every person eau become a successful English learner. The main thing is to sort【64】and develop a set of successful language learning techniques, which, indeed,【65】from one learner to another.
1. Have curiosity to learn English and cognate something new, opening unexplored horizons of knowledge. Curiosity is a【66】force, which will push you up in English learning. You can be inquisitive about language, culture, traditions, or even people who【67】this country. You should always try to find a force, which will make you tick and help you advance with rapid strides. Someone calls it motivation; others name it an eager【68】to learn. No matter how it is called, the main thing is that it brings lasting and positive results.
2. Treat realistically a【69】of your goal, your potential and your time. Remember that English learning is impossible to limit within some frameworks. Because language learning has a beginning, but it does not have an exact ending, as English learning prolongs in the whole【70】of your life.
(51)
The Cambridge Preliminary(预备的) English Test (PET) is the second level of the Cambridge exams in English for Speakers of Other Languages, that is, people who do not speak English. It is an intermediate(中级的) level exam. PET recognizes the ability to cope with everyday written and spoken communications.
Who is PET for？
PET is designed for people whose English is adequate(足够的) for many practical purposes, including work, study and social situations.
Candidates should have a wide grasp of vocabulary and be able to use appropriate communication styles for a variety of situations.
PET is taken by more than 80,000 people each year in more than 80 countries, and is a valuable qualification for anyone who wants to work or study abroad or to develop a career in international business.
Why choose PET？
PET covers the four main language skills—reading, writing, listening and speaking, as well as testing grammar and vocabulary. It therefore provides evidence of practical skills. Studying for PET is a popular way to improve your language skills and use them in a wide range of contexts(上下文). PET is recognized by many employers and educational institutions as proof of intermediate level English skills.
…
Full name of PET: the Cambridge【46】
Level of the exam:【47】
Designed for: speakers of【48】
Requirements for candidates: 1) a large【49】, and
2) the ability to【50】in various situations
High Blood Pressure
There is evidence that the usual variety of high blood pressure is，in part，a familial disease．Since families have similar genes as well as similar environment，familial diseases could be due to shared genetic influences，to shared environmental factors，or to both．For some years，the role of one environmental factor commonly shared by families，namely dietary salt，has been studied at Brook—haven National Laboratory．These studies suggest that chronic excess salt ingestion(摄取)can lead to high blood pressure in man and animals．Some individuals，however，and some rats consume large amounts of salt without developing high blood pressure．No matter how strictly all environmental factors were controlled in these experiments，some salt-fed animals never develop hypertension(高血压)whereas a few rapidly developed very severe hypertensions followed by early death．These marked variations were interpreted to result from differences in genetic constitution．
By mating in successive generations only those animals that failed to develop hypertension from salt ingestion，a resistant strain(the R strain)has been evolved in which consumPtion of large quantities of salt fails to influence the blood pressure significantly．In contrast，by mating only animals that quickly develop hypertension from salt，a sensitive strain(the S strain)has also been developed．
The availability of these two strains permits investigations not therefore possible．They provide a plausible laboratory model on which to investigate some clinical aspects of the human developing methods by which genetic susceptibility(敏感性)of human beings to high blood pressure can be defined without waiting for its appearance．
The main idea of this passage is__________． 查看材料
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