Lesson26KeeptheCandleBurning (2).ppt

1、Lesson 26,Keep the Candle Burning,candle,a match,matches,lighter,Candleholder,jar,a dish,What do we need?,1.a candle,2.a candleholder,3.a big glass jar,4.a shallow dish,5.some water,6.Matches or a lighter,What do we do?,1、put the candle in the candle holder,2.put the candleholder on the dish,3.fill

2、the dish half full with water,4.light the candle.,5.Let the candle burn for two or three minutes.,6.Carefully put the jar over the candle until the top of the jar rests on the dish.,7.Examine the water in the jar.,1、put the _in the _,2、put the _ on the _,3、Fill _ half full with_,4、_the candle,5、Let

3、the candle _ for two or three minutes,candle,candleholder,candleholder,dish,dish,water,Light,burn,6、Carefully put the _ over the _ until the top of the jar rests on the dish.,7、Examine the _ in the jar.,jar,dish,water,What can you see?,What is happening?,Guess what will happen :,1. Candles keep burn

4、ing.( ),2.Candles stop burning. ( ),5.The water inside the jar will rise. ( ),3 .The water inside the jar will be still. ( ),4.The water inside the jar will go down. ( ),NO,Yes,NO,NO,Yes,.How far does the water rise and fill the jar?,.Why?,The water rises and fills about one fifth of the jar.,Becaus

5、e there is about one fifth oxygen in the air .The candle uses up all the oxygen in the jar.,1、As the candle burns ,it uses up oxygen in the jar .,2、When the candle stops burning ,it has used up all the oxygen in the jar .,3、Then the water inside the jar rises .,4、About one fifth of the air is made up of oxygen ,so the water rises and fills about one fifth of the jar.,1. 当蜡烛停止燃烧时，它已用光了空气中所有的氧气。 When the candle _ _, it _ _ _ all the oxygen in the air. 2. 我们班里五分之三是女生。 _ of the students in our class are girls. 3. 为了完成那项工作，他工作了十个小时。 _ _ the work, he has worked _ ten ho