人教全日制普通高中英语(必修)高三UNIT4-3(在线收听

The study of natural history is not something to be left to biologists. In fact, their capacity in terms of the time they can spend away from their offices is very limited. Even if all professors in universities and research institutes could devote all their time to the study of nature, their contribution, although important, would still be quite small. To the study of natural history the contribution of other people with an interest in nature has always been equally important.
 
       In many countries, groups of people who share an interest in nature have formed natural history clubs. They regularly get together to explore the environment near their hometown. Some people have a general interest in nature, while others try to become specialists. Therefore, large natural history societies usually have different groups to study and observe birds, plants, insects or other wildlife.
 
      Some clubs have a long history, and many started at schools with the help of a biology teacher. Natural history societies with a long history often have a good library and modern equipment to explore nature. They publish their own magazines, in which they report their observations and research. Even some nature clubs run by students aged .between 12 and 25, are able to reach very high scientific standards. This is exactly why their contribution is so valuable. While governments, universities and research institutes only have a limited budget to do fieldwork, people whose hobby it is to study botany can devote a great deal of money and time to it.
 
      Botany is very suitable as a hobby. Besides a good Flora, very little special equipment is needed. The most important things are a magnifying glass (at least 8x), a short ruler, a pen and a notebook. A Flora is a special book to identify plants. The Flora of the British Isles, for example, is a book that describes all plants that are native to the British Isles. It is usually possible to find the name of a plant in about ten minutes, especially for people who are experienced at working with a Flora. To find the name of a plant species it is often necessary to have a close look and count the male and female organs in the flowers. To see this clearly, a magnifying glass is essential. Flowers are not always needed to identify the plant. Once the name has been found, it is important to make notes of the exact place where and the date when the plant was found.
 
      Plants grow in communities, and plant sociology is the branch of botany that studies this phenomenon. By making a careful analysis of the plant growth in a square metre, it is possible to find out what type of plant community occupies the land. Some plant communities are made up of very common plant species. Others may contain very special, endangered plant species. Knowing more about nature will help us realise which parts of our environment deserve our protection.
 
      It is not necessary for you to live in the countryside to take an active interest in botany. Any environment, whether urban or rural, offers a variety of different habitats, in which plants can be studied. Nature often has to put up a fierce struggle to survive in the city. Still, every city contains natural habitats, in which wild plants have found their home. To study, describe and protect them makes an important contribution to science and an effort to care for the environment.

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