1、Unit 4Unit 41Staying healthyStaying healthyModule 保持保持 健康健康PIGGY BANKGOLD MINELook and learnLook and learnWhats the matter with Kitty?She has got a cold.1 12 23 33-1PIGGY BANKGOLD MINEHealth problemsa colda fevera sore throat/3-3PIGGY BANKGOLD MINEHealth problemsa headachea stomach achetoothache/3-2
2、Look and learna headachehedeIk a stomach achestmk,eIk toothachetu,eIk a colda feverfi:v s:rut a sore throatPIGGY BANKGOLD MINERead and writeRead and writeHow did these people feel?Complete each sentence.1.Joes stomach hurt.He has a _.2.Larry didnt go to the dentist for years.Now he has bad _.3.Alan
3、stayed at home from school because he had a cough and a _.4.Bens head hurt.He has a _.stomach achetoothachecoldheadacheListen and sayListen and sayPIGGY BANKGOLD MINE1 12 22-1Why do I always have a headache?Its because you watch too much television,Im afraid.What should I do?You should watch less te
4、levision.too much+u.n 太多PIGGY BANKGOLD MINE2-21 12 2Why do I always have a cold?Its because you dont wear enough clothes,Im afraid.What should I do?You should wear more clothes.Read,match and sayRead,match and sayPIGGY BANKGOLD MINECan you give the correct answers?5-11 12 23 34 45 5PIGGY BANKGOLD MI
5、NEIts because you eat too much spicy food,Im afraid.Its because you eat too many rice dumplings,Im afraid.Its because you dont have enough exercise,Im afraid.Its because you eat too much sweet food,Im afraid.Why do I always have a stomach ache?Mr Yang5-21 12 23 34 45 5PIGGY BANKGOLD MINEIts because
6、you eat too much spicy food,Im afraid.Its because you eat too many rice dumplings,Im afraid.Its because you dont have enough exercise,Im afraid.Its because you eat too much sweet food,Im afraid.Why do I always have a sore throat?Mr Zhu5-31 12 23 34 45 5PIGGY BANKGOLD MINEIts because you eat too much
7、 spicy food,Im afraid.Its because you eat too many rice dumplings,Im afraid.Its because you dont have enough exercise,Im afraid.Its because you eat too much sweet food,Im afraid.Why do I always have a fever?Mrs Tang5-41 12 23 34 45 5PIGGY BANKGOLD MINEIts because you eat too much spicy food,Im afrai
8、d.Its because you eat too many rice dumplings,Im afraid.Its because you dont have enough exercise,Im afraid.Its because you eat too much sweet food,Im afraid.Why do I always have toothache?Miss Ma5-51 12 23 34 45 5PIGGY BANKGOLD MINEAsk and answerAsk and answer2-11 12 2Suppose you are one of Doctor
9、Chens patients.Talk like this:S1:Why do I always have(a)_?S2:Its because you,Im afraid.S1:What should I do?S2:You should _ more/less/fewer _.PIGGY BANKGOLD MINE2-21 12 2In pairs,talk about what Doctor Chens patients should do.S1:Why does(name)always have(a)_?S2:Its because he/she,Im afraid.S1:What s
10、hould he/she do?S2:He/She should _ more/less/fewer _.PIGGY BANKGOLD MINEDiscuss and writeDiscuss and writeMedical recordName:_Age:_Health problem:_ _Advice:_ _学生填写病历记录。学生填写病历记录。staying healthystaying healthyModule 保持保持 健康健康How do you Drink milkEat vegetablesEat unhealthy snacksWatch TV too muchExerc
11、ise every dayUsually go to bed earlyRead a lot of books中央厚、边缘薄焦点FF焦距f主光轴几个基本概念光心经过光心的光线传播方向不发生改变凸透镜成像有什么规律吗？问题与猜测：也可用蜡烛先用你自己设计的方法测出实验用的凸透镜的焦距f，并记录下来。提示：太阳光可以看作是平行光。平行光都会会聚于焦点。（1）在阳光下固定一凸透镜，让阳光垂直照射凸透镜；（2）在凸透镜后面放一白纸，前后移动白纸，直到在白纸上得到一个最小的亮点为止固定白纸位置；（3）用刻度尺测出凸透镜和白纸的距离即是凸透镜的焦距 物距u像距v改变光源、透镜与光屏的位置，让发光体经透镜后
12、成放大、缩小、等大的像，观察像是正立还是倒立的，记录好物距与像距，换不同焦距的透镜重复实验实像与虚像实像（real image）是能在光屏上呈现的像，它是由实际光线会聚而成的。实像虚像（virtual image）不能在光屏上呈现出来，只能用人眼通过透镜观察。透镜焦距透镜焦距f/cm实验实验次数次数像的像的大小大小像的像的正倒正倒像的像的性质性质物距物距u/cm像距像距v/cm探究实验记录表大于2倍等于2倍小于2倍但大于小于实实实虚中央薄、边缘厚FF当u2f时，像距v应满足：，题中给出像距v=16cm，分析:本题给出的信息是成倒立缩小的实像，说明物距应满足 ；例题：某同学在“研究凸透镜成像”的实验中，光屏移动到离凸透镜16cm 处，得到烛焰倒立、缩小的像，他使用的凸透镜的焦距为：.cm .cm .12 cm .18 cmf v 2f即：f 16 cm 2f只有C选项符合该条件 一、已知 f=10cm，如果把物体放在25cm的地方，则在光屏上会得到一个（），（）的（）像。二、如果要得到一个放大的实像应把物体放在（)与（）之间，如果要得到一个放大的虚像应把物体放在（）之内。倒立缩小实1倍焦距2倍焦距焦距课堂练习：BAFABF作图题：已知凸透镜的位置以及焦距，通过作光路图确定物体AB的像AB的位置。在下列方框中，填入适当的光学元件
