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课件网) Lesson 26 Keep the Candle Burning Unit 5 Look into Science We will learn The new words: holder, shallow, lighter, match, examine, oxygen Important and difficult points: ①Let the candle burn for two or three minutes. ②When the candle stops burning, it has used up all the oxygen in the air. ③How far does it rise ④Because about one fifth of the air is made up of oxygen, the water rises and fills about one fifth of the jar. Do you like doing science experiments Why or why not Lead in Think about it What will happen if you put a jar upside down over a burning candle Listen and imitate Language points 1. When the candle stops burning, it has used up all the oxygen in the air. 当蜡烛停止燃烧时，它就用完了空气中所有的氧气了。 use up意思是“用完、用光”，这是“动词 + 副词”短语。这类短语用名词作宾语时，名词可用在副词前，也可用在副词后；用代词作宾语时，代词则必须用在副词前。 e.g. I gave Li Ming a lot of pencils, but he has used them up already. 我给了李明很多铅笔，但他已经把它们都用完了。 half/hɑ f/ adj.一半的 n.半； 一半 half 意为“一半的”，作形容词。 half an/a ＋名词，意为“半个……”。 e.g. half an hour 半个小时 half a day 半天 half an apple 半个苹果 2.Fill the dish half full with water. Language points half of…意为“一半的……”，后接名词时，一般要在名词前加the、形容词性物主代词或指示代词等。 此结构作主语时谓语动词和of后的名词保持一致。 即：若of后的名词是复数则谓语动词用复数形式； 若of后的名词是可数名词单数或不可数名词，则谓语动词用单数形式。 Language points light/la t/ v. 点燃 3.Light the candle. Language points light的其他用法： n.可意为“光线，电灯”。作“光线”讲时为不可数名词，作“电灯”讲时为可数名词 The light was beginning to fail. 天色渐暗。 Don’t forget to turn off the lights when you leave. 当你离开的时候不要忘了关灯。 adj.意为“浅色的，轻的”。 Rose likes the light green skirt. 罗丝喜欢那条浅绿色的短裙。 You can carry this bag. It’s very light. 你可以拿这个包。它很轻。 until/ n't l/ conj.直到……为止 e.g. I’m going to stay here until Saturday and start on Sunday. 我打算在这里一直呆到星期六，然后星期日出发。 用于肯定句中，主句的谓语动词一般是延续性的。 用于否定句中，主句的谓语动词一般是非延续性的。 e.g. I didn’t begin the work until he came back. 直到他回来我才开始这项工作。 4.Carefully put the jar over the candle until the top of the jar rests on the dish. Language points Language points 5. Because about one fifth of the air is made up of oxygen, the water rises and fills about one fifth of the jar. 因为组成空气的成分大约五分之一是氧气，所以水会上升并且填充瓶子的大约五分之一。 be made up of意为“由……组成”，后加名词或代词作介词宾语。 e.g. This grade is made up of ten classes. 这个年级是由十个班组成的。 one fifth意思是“五分之一”，这是一个分数。分数的表达一般遵循以下规则：分子用基数词，分母用序数词；当分子大于一时，分母要用复数形式；并且其中的连字符号有时可以不要。 e.g. one-fourth 四分之一 three fifths 五分之三 1.Read the lesson and fill in the blanks. Let’s do th ... ...
