,Unit 4,Amazing Science,W,e,l,c,o,m,e,t,o,t,h,e,u,n,i,t,Topic 3,I dont think aliens can be found in space.,Section C,New words,solar,太阳系,Roman,古罗马的，罗马帝国的,diameter,直径,storm,风暴，暴雨,gravity,重力，引力，地心引力,limit,限制，限定,Teaching aims and demands,1.Learn the new words and expressions:,storm,search,dry,base on,Its diameter is 53%as long as that of the earth.,2.Review the passive voice.,3.Learn something more about Mars.,1.,the fourth planet from the sun,2.,the Red Planetthe rocks,soil and sky are a little red,3.,20 140,4.,There are season changes.,How much do you know about Mars?,Find out information about Mars.,2.,But during spring and summer,strong storms can cover the whole surface of Mars.,3.,It goes around the sun,at distance of,about 228 million kilometers.,4.,Its,a quarter,as big as the earth.,5.,The,gravity,on the surface of Mars is about,one third,as strong as,it,on the earth.,6.,The temperature on Mars is between-140,o,C 20,o,C.,7.,The air has only 0.13%oxygen.,1,.Mars looks like a red and orange ball.Its very beautiful.,Ask and answer,looks like;during;storms;cover;goes around;a quarter;gravity;one third;temperature;,0.13%oxygen,Retell,Discuss the following crazy questions with your partners.,1.Does Mars have a good climate for a garden?,2.Is Mars a useful place to dry fruit?,3.Is Mars a good place for human beings?,4.Is Mars a comfortable place for heavy people?,Pairwork,a spacesuit,is like a spaceship.,Study,words,Hubble Space Telescope,They can give us,a clearer view,of the plants in space.,telescope,s,Study,words,Explanation,1.Mars is the fourth planet from the sun in our solar system and is named after Mars,the Roman god of war.,火星在我们太阳系中是太阳的第四颗行星，它是以罗马的战神,Mars,命名的。,name,在这里作动词，意为“命名，给,取名”。如：,They named their son Bruce.,他们给儿子取名布鲁斯。,be named after,被命名为,，以,命名 如：,Chinas first lunar probe was named after Change I,中国的第一颗月球探测器被命名为“嫦娥一号”。,2.Mars goes around the sun at a distance of about 228 million kilometers.,火星在相隔大约,228 000 000,公里的地方绕着太阳转。,at a distance of,相隔,介词短语在句中作状语。如：,Put the stone at a distance of about 20 meters from the door.,把这块石头放在离房门大约,20,米的地方。,The police followed the thief at a distance.,警察远远地跟着那个小偷。,3.So a person who weighs 90 kilos on the earth weighs only 36 kilos on Mars.,所以，一个在地球上重,90,公斤的人在火星上只重,36,公斤。,（,1,）这里,who weighs 90 kilos on the earth,是一个定语从句，对,a person,进行修饰或限制。这里,who,作,weighs,的主语不能省略。而且要注意，由于被修饰词,a person,是第三人称单数，所以这里用（,who,）,weighs,，而不用,weigh,。,who,为引导词，常用的引导词有,who,，,that,which,where,等。一般被限制词是人时，用,who,或,that,引导；被修饰词是事物时，用,that,或,which,引导。当引导词不作从句的主语时，可以省略。,He is the people(who)I am looking for.,他就是我正在寻找的人。,A cage is a place(where)birds or animals are kept.,笼子就是一个饲养鸟兽的地方。,2,）,one the earth,意为“在地球上”。,on earth,意为“在地球上，在世界上”，当意为“究竟，到底”时，常放在特殊疑问代词之后。如：,What on earth are you doing?,你究竟在干什么？,4.Scientists are still searching for more information about Mars.,科学家们仍然在搜寻关于火星的更多的信息。,search sth.for sb./sth.,搜索，搜寻，搜查，查找 如：,The police searched the whole village for the thief,at last they caught him.,警察搜查整个村庄找这个贼，最后他们抓住了他。,in search of,寻找，查找 如：,She went into the kitchen in search of a drink.,她进了厨房，想找点喝的。,5.This film is based on a science fiction.,这部电影是以一部科幻小说为基础的。,be based on,以,为基础（根据），取材于,如：,The novel is based on a real story.,这篇小说是以一个真实的故事为基础的,课堂互动,S,：老师，课文中有一个句子,Its diameter is 53%as long as that of the earth.,其中的,as long as,是表示我们前一话题学过的“只要,，就,的意思吗？,T,：不对。我们前一话题学的,This method worked well at night as long as the weather was good.,中的,as long as,确实是“只要,，就,”,的意思。但本课中的这个句子是一个表示原级比较的句型，常用“,as,形容词原级,as”,表示。因此原句表示“它的直径是地球直径的,53,长”的意思。而且，原级比较还可以表示事物之间倍数、分数、百分比等数量关系，其一般结构为：,A,谓语动词倍数,/,分数,/,百分数,as,形容词原级,as,B,。,如本课中还有一个这样的句型：,The gravity on the surface of Mars is about two-fifths as strong as it is on the earth.,火星表面的吸力大约是地球表面引力的五分之二。,Homework,Suppose you are Maria.Please write another diary after watching the movie about aliens.,