Đáp án A Thông tin: có nhiều cách để khuyến khích dạy theo nhiều cách In our classroom, we work in various ways. We encourage our pupils to use the library, and we teach them the skills they need in order to do this effectively.
Orchids are unique in having the most highly developed of all blossoms, in which the usual male and female reproductive organs are fused in a single structure called the column. The column is designed so that a single pollination will fertilize hundreds of thousands, and in some cases millions, of seeds, so microscopic and light they are easily carried by the breeze. Surrounding the column are three sepals and three petals, sometimes easily recognizable as such, often distorted into gorgeous, weird, but always functional shapes. The most noticeable of the petals is called the labellum, or lip. It is often dramatically marked as an unmistakable landing strip to attract the specific insect the orchid has chosen as its pollinator. To lure their pollinators from afar, orchids use appropriately intriguing shapes, colors, and scents. At least 50 different aromatic compounds have been analyzed in the orchid family, each blended to attract one, or at most a few, species of insects or birds. Some orchids even change their scents to interest different insects at different times. Once the right insect has been attracted, some orchids present all sorts of one-way obstacle courses to make sure it does not leave until pollen has been accurately placed or removed. By such ingenious adaptations to specific pollinators, orchids have avoided the hazards of rampant crossbreeding in the wild, assuring the survival of species as discrete identities. At the same time they have made themselves irresistible to collectors.
Read the following passage and mark the letter A , B , C , or D on your answer sheet to indicate the correct answer to each of the questions
The advent of the Internet may be one of the most important technological developments in recent years . Never before have so many people had access to so many different sources of information . For all of the Internet's advantages , however , people are currently becoming aware of some of its drawbacks and are looking for creative solutions . Among the current problems , which include a general lack of reliability and numerous security concerns , the most crucial is speed .
First of all , the Internet has grown very quickly . In 1990 , only a few academics had ever heard of the Internet . In 1996 , over 50 million people used it . Every year , the number of people with access to the Internet doubles . The rapid growth has been a problem . The computer systems which run the Internet have not been able to keep up with the demand . Also , sometimes , a request for information must pass through many routing computers before the information can be obtained . A request for information made in Paris might have to go through computers in New York , Los Angeles and Tokyo in order to obtain the required information . Consequently , the service is often slow and unpredictable. Service also tends to be worse when the Internet is busiest - during the business day of the Western Hemisphere - which is also when companies need its service the most.
Some people are trying to harness the power of networked computers in such a way as to avoid this problem . In 1995 , a group of American universities banded together to form what has come to be known as Internet II . Internet II is a smaller , more specialized system intended for academic use . Since it is more specialized , fewer users are allowed access. Consequently , the time required to receive information has decreased . Businesses are beginning to explore a possible analogue to the Internet II . Many businesses are creating their own " Intranets " . These are systems that can only be used by the members of the same company . In theory , fewer users should translate into a faster system . Intranets are very useful for large national and international companies whose branches need to share information . Another benefit of an Intranet is an increased amount of security . Since only company employees have access to the information on the Intranet , their information is protected from competitors . While there is little doubt that the Internet will eventually be a fast and reliable service , industry and the academic community have taken their own steps toward making more practical global networks .
In the passage , which following is NOT true of the Internet ?
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