阅读理解。 Science Daily (Apr. 27, 2008)-- Dutch ecologist Roxina Soler and her c
题型：广东省期中题难度：来源：
discovered that subterranean (地下的) and aboveground herbivorous (食草的) insects can
communicate with each other by using plants as telephones. Subterranean insects issue chemical
warning signals through the leaves of the plant. This way, aboveground insects are warned that the
plant is already "occupied".
Aboveground, leaf-eating insects prefer plants that have not yet been occupied by subterranean
root-eating insects. Subterranean insects send out chemical signals through the leaves of the plant,
which warn the aboveground insects about their presence. This messaging makes it possible for
spatially-separated insects to avoid each other, so that they do not compete for, the same plant.
In recent years it has been discovered that different types of aboveground insects develop slowly
if they feed on plants that also have subterranean insects and "vice versa (反之亦然). It seems that a
mechanism (机制) has developed through natural selection, which helps the subterranean and
aboveground insects to communicate with each other. This avoids unnecessary competition.
Through the "green telephone lines", subterranean insects can also communicate with a third party,
namely the natural enemy of caterpillars (毛虫). Parasitic wasps (寄生蜂) lay their eggs inside above
ground insects. The wasps also benefit from the signals sent by the leaves, as these help them find more
insects for their eggs.
The communication between subterranean and above- ground insects has only been studied in a
few systems. It is still not clear how widespread this phenomenon is, say the researchers.
B. By giving off particular smells.
C. By making soft and beautiful sounds.
D. By the signals sent by parasitic wasps.
B. choose to leave the plant
C. compete for the same plant
D. fight with the root-eating insects
B. are not occupied by mot-eating insects
C. have more green leaves
D. have more subterranean insects
A. Aboveground insects.
B. Root-eating insects.
C. Caterpillars.
D. Parasitic wasps.
B. How do animals avoid competition?
C. Insects use plants as telephones
D. When plants have subterranean residents
答案
举一反三
everyday household products．
In a study 25 women had their homes and bodies tested for 89 environmental pollutants-including
pesticides (***虫剂) and chemicals found in plastics and cleaning products．On average 20 chemicals
were found on their bodies or in their homes．
Much is unknown about the possible health effects of chemicals in everyday household products．
But certain chemicals-like phthalates (邻苯二甲酸盐) found in plastics-have been linked to potential
health risks,including higher risks of certain cancers,though the evidence mainly comes from research
on lab animals．Other household chemicals are known to harm the skin,eyes and airways-and may
worsen asthma (哮喘)．Many more chemicals found remain untested．
Chemicals likely come from a range of sources,so it is not always clear how to reduce people"s
exposure,according to Dr．Rebecca Altman,the lead researcher on the new study．"However," she
said,"there are still measures people can take．"
In the original study,she noted,women were given advice based on the particular chemicals they
were exposed to-such as using fragrancefree washing liquid and personalcare products．
For the current study,Altman and her colleagues interviewed two dozen women who"d taken part in
the previous study to see how they would react to information about their household chemical exposures．They found that the women were generally surprised at the range of chemicals found in their homes and
bodiesThey were also surprised that even some banned things were found．
With many questions about the health effects of household chemicals unanswered,some experts worry
that giving people information about their everyday expo
sures will cause unnecessary fear．However,theresearchers found that the women in their study were typically not alarmed,and instead wanted "more
rather than less" information on the issue．
le some have good effects．B．Longterm exposure to them is certain to cause a deadly illness．
C．In the study it was found that certain chemicals can cause cancers．
D．It is uncertain what effects some chemicals have on health．
B．things that look like fine threads growing in the body
C．the passage between rows of rooms in a building
D．the area just inside the front door of a building
B．fragrant products may contain harmful chemicals
C．it is unnecessary to inform people about the study results
D．further study on everyday products should be done immediately
B．They refused to be subjects for the study any more．
C．They were afraid of getting bad news about their health．
D．They would like to know more related information．
根据短文内容，从短文后的选项中选出能填入空白处的最佳选项.选项中有两项为多余项。
familiar, the reading comprehension is no problem, and you are speaking quite fluently. 1
First of all, remember that you are not alone. Listening is probably the most difficult job for almost
all learners of English as a foreign language. 2 what you need to do is to find listening resources. The
Internet is really a useful tool for English students. You can download The RealPlayer from RealMedia.
com. The Real Player allows you to use the Internet like a radio station.
Once you have begun to listen on a regular basis, you might still be frustrated(受阻)by limited
understanding 3
Here is some of the advice I give my students:
Accept the fact that you are not going to understand everything.
Stay relaxed when you do not understand, and try listening to the material for more times.
Do not translate everything into your native language .
4 Don"t concentrate on detail until you have understood the main ideas.
Listen to something you enjoy.
I remember the problems I had in understanding spoken German when I first went to Germany. In
the beginning, when I didn"t understand a word, I insisted on translating it in my mind. 5 Then, after
the first six months, I discovered two extremely important facts; Firstly, translating creates a barrier
between the listener and the speaker. Secondly, most people repeat themselves constantly. By remaining
calm, I noticed that even if I didn"t pay much attention I could usually understand what the speaker had
said.
A. What should you do?
B. But listening is a problem for most of the beginners!
C. However, after several weeks, I got used to the grammar rules
D. The most important thing is to listen as often as possible.
E. This method usually resulted in confusion.
F. Listen for the general idea of the conversation.
G. But you can"t follow a native English speaker at all!
| A. occurred B. extended C. tragedy D. fined E. ignore F. concerns G. suspension H. inevitably I. illegal J. must-have | ||||||
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| Today, there are many avenues open to those who wish to continue their education. However, nearly all require some 1 in one"s career in order to attend school full time. Part-time education, that is, attending school at night or for one weekend a month, tends to drag the 2 out over time and puts the completion of a degree program out of reach of many people. 3 , such programs require a fixed time commitment which can also impact 4 on one"s career and family time. Of the many 5 to teaching and learning, however, perhaps the most flexible and accommodating is that called distance learning. Distance learning is an educational method, which allows the students the 6 to study at his or her own pace to achieve the 7 goals, which are so necessary in today"s world. The time required to study may be set aside at the student"s convenience with due 8 to all life"s other requirements. Besides, the student may 9 in distance learning courses from virtually any place in the world, while continuing to pursue their chosen career. Tutorial assistance may be 10 through regular airmail, telephone, fax machine, teleconferencing and over the Internet. Good distance learning programs are characterized by the inclusion of a subject 11 tool with every subject. This precludes(排除) the requirement for a student to travel away from home to take a test. Another characteristic of a good distance-learning program is the 12 of the distance-learning course with the same subject materials as those students taking the course on the home campus. The resultant diploma or degree should also be the same whether distance learning or on-campus study is e mployed. In the final analysis, a good distance learning program has a place not only for the 13 students but also the corporation or business that wants to work in partnership with their employees for the educational benefit, professional development, and business growth of the organization. 14 distance learning programs for their employees gives the business the advantage of retaining(保留) career-minded people while 15 to their personal and professional growth through education. | ||||||
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