Unit 12 Mainly revision

扩展资料

一

Universe

　　Universe is the whole of space, including all the stars and planets. Distance in the universe is measured in light years, and a light year is the distance light travels in a year, about 9.46× kilometers. Today scientists have recognized stars about nine billion (9× ) light years away from us, but certainly there are stars farther away. The earth we live on is tiny compared with the sun, but the sun is only one of a hundred billion or more stars that make up a single galaxy(星系), or group of stars, called the Milky Way (银河系), and the Milky Way is only one galaxy out of a million galaxies that make up the universe.

Satellite

　　A satellite is a small heavenly body that moves around a planet. The earth has one  satellite (the moon), while some of the other planets have more. These satellites are called natural satellites. Manmade objects which circle the earth or other planets are called artificial satellites(人造卫星). Artificial satellites can be used for many different purposes. Weather satellites help in forecasting(预报) the weather. They carry special cameras which can take photos of clouds all over the earth from space. Scientists are able to forecast the weather by studying these photos. Communication satellites are higher from the surface of the earth than weather satellites. They carry special instruments which can pass on or relay(转播) radio and television programmes or telephone messages from one station to another. Scientific satellites carry scientific instruments which can gather various information about space. Another kind of satellites are sent to the moon or the planets to get information about them and take their photos very near to them.

二　怎样学好被动语态

　　被动语态（passive voice）是初中英语学习的重难点之一，是同学们容易出错的语法项目。那么，怎样才能学好被动语态呢？

一、打破思维定势，树立“被动”意识

　　从初一到初三我们一直在学习主动语态，逐渐形成了用主动语态处理语言的思维习惯，用被动语态思维的意识却相对薄弱。而英语中的动词有两种语态，所以，同学们首先要树立两种语态，两者兼顾、全面思考问题的意识。

二、抓住重点，各个突破

　　1．牢固掌握被动语态结构形式，即be+及物动词的过去分词。这是树立被动语态意念的关键，也是学好被动语态的主线和重点。

　　2．灵活运用助动词be的不同形式。即在各种时态中及各种句型中的变化，如一般现在时态中be有is, am, are三种形式。一般过去时态中be有was, were两种形式。这两种时态的一般疑问句，否定句及特殊疑问句都是通过be来体现的，而带有情态动词的被动语态则是通过情态动词来体现的。这些变化形式同学们不妨在草稿纸上多练习几遍，就象我们在记数学、物理或化学公式一样，久而久之也就记住了。

　　3．记牢过去分词，尤其是不规则动词的过去分词。把不规则动词的过去分词分门别类，使其趋于系统、条理化。例如：根据不规则动词的原形、过去式、过去分词的规律，把它们分为AAA型，如hurt, hurt, hurt; ABB型，如hear, heard, heard; ABC 型，如forget, forgot, forgotten等。另外，我们还可以边学边记，及时发现问题，及时巩固。

三、循环往复，举一反三

　　1．加强“横向”练习。即主动句变被动句，被动句变主动句。如果是一个主动句，看它能否变成被动句；若是被动句，怎样变成主动句。通过反复的练习，加强对被动语态的理解。

　　2．重视“纵向”练习。也就是对一个被动句进行不同时态的变化。如：Trees are cut down.在一般过去时态下变成Trees were cut down.带有情态动词的变化为Trees can't be cut down.等，从而达到熟练运用被动语态的目的。

三　The earth

　　Scientists are discovering more about the universe and the Earth's place in it. They can observe new and dying stars through telescopes. They listen to radio signals from objects in deep space. They also send spacecraft to explore the planets closely. According to the scientific information, no other planet but Earth has the air, water, and vegetation necessary for life.

　　The Earth has the best position among the nine planets that revolve around the sun. It doesn't travel too near or too far from the sun. It receives the necessary amount of heat and light. The air around the Earth keeps out the sun's dangerous rays. The sun dries up some of the ocean water into clouds and the winds blow the clouds over the land. In this way ocean water falls as rain upon the land. As the Earth revolves around the sun, the seasons change from autumn and winter to spring and summer. The Earth is green with vegetation. Without the Earth's special environment, there would be on life. If we change the environment, we may destroy some of the life on Earth.

　　Thousands of years ago the ancient people found out that days were longer in summer than in winter, and nights were shorter. They knew that this had a great deal to do with the changes of the seasons and the growth of plants and animals. They determined through generations of painstaking(努力的) observation that the day was shorter in the Northern Hemisphere(北半球) on the 22nd of December, after which it gradually grew longer until the 21st of June, when the day was the longest in the year and the night was the shortest. After that, the day would begin to shorten again gradually. In the beginning, the actual dates of these two days had to be calculated for each individual year, and depended on what kind of calendar was being used.

　　The first calendar to fix these days on definite dates of the year was the solar calendar, which had 365 days in a year and - every four years - a "leap-year"(润年) with one extra day.

Venus

　　Venus（金星） is our nearest neighbour in space. It is only 42 million kilometres away. We know that in some ways, Venus is like the earth. It is like the earth to go round the sun. It is almost as big as the earth, too.

　　Earth people can't live without air, but our neighbour doesn't have this kind of air. There is very little water on Venus. Still, some scientists believe there may be lives on it. These scientists think that some microbes（微生物） may be able to live on Venus. They are not sure about this but one thing---earth people could not live on Venus.

根据短文内容，选择最佳答案。

　　1.Venus is ______the earth in space.

　　　A. far away from   B. far from   C. near to   D. nearer to

　　2.Venus is ______our planet.

　　　A. bigger than    B. smaller than    C. as big as    D. as larger as

　　3.Venus is ______.

　　　A. satellite          B. one of the sun's planets

　　　C. the earth planet    D. one of the earth's planets

　　4.There is no _______on Venus.

　　　A. water    B. air    C. microbes    D. A and C

　　5.The scientists believe that ______.

　　　A. there is no life on Venus    B. we could not live on Venus

　　　C. we can't find some microbes on Venus    D. there are some animals on Venus

参考答案：1-5  CCBBB

四　关于宇宙的英语词汇

　　Earth 地球

　　moon  月亮

　　sun 太阳

　　star   星

　　planet  行星

　　Venus   金星

　　Jupiter   木星

　　Mercury  水星

　　Mars  火星

　　Saturn   土星

　　Uranus   天王星

　　Neptune  海王星

　　Pluto   冥王星

　　constellation   星座

　　the Bull   金牛座

　　the Ram 白羊座

　　the Crab   巨蟹座

　　the Twins  双子座

　　the Scorpion  天蝎座

　　the Lion   狮子座

　　the Balance 天秤座

　　the Virgin  处女座

　　the Water Bearer 水瓶座

　　the Goat   山羊座

　　the Archer   人马座

　　the Fishes  双鱼座

　　asteroid   小行星

　　comet   彗星

　　equator   赤道

　　galaxy   银河系

　　gravity  重力

　　latitude  纬度

　　longitude   经度

　　meteor  流星

　　meteorite  陨星

　　nebula  星云

　　orbit  轨道

　　revolution   公转

　　satellite   卫星

　　solar system   太阳系

　　shooting star 流星

　　space 太空

　　spaceship  宇宙飞船

　　sphere  天体，星

　　the Plough 北斗七星

　　the stars at dawn 晨星

　　celestial body 星球

　　star map 星图

　　galaxy 星系

　　nebula 星云

　　starquake星震

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