Lesson 17: Save the Tigers,1) the number of 2) balance的用法 3) danger的用法,I. Learning aims:,Master the new words: century, fur, symbol, courage, brave, chain, balance, reason, disappear, kill, cut, decrease,II. Learning important and difficult points:,New Words,century fur symbol courage brave chain balance reason disappear kill cut decrease,Think About It,Where can you usually see a tiger? Do you think tigers need our help? Why or why not?,Language Points,At the beginning of the 20th century, the number of tigers in the wild was around 100 000. 在二十世紀初期，野生老虎的數(shù)量大約是十萬。 the number of是固定短語，意為“的數(shù)量”，后接可數(shù)名詞復(fù)數(shù)，但中心詞是number，所以謂語動詞要用單數(shù)。如： The number of students in our school has grown from 1,000 to more than 1,500. a number of為量詞短語，意為“許多；大量”，相當于a lot of或lots of，中心詞是該短語所修飾的可數(shù)名詞復(fù)數(shù)，所以作主語時，謂語動詞用復(fù)數(shù)形式。 如： A number of students like playing computer games.,2. It helps keep the number of other wild animals in balance. 它可以幫助保持其他野生動物的數(shù)量平衡。 balance 在句中用作名詞，意為“平衡；均衡”，常用短語be out of balance，意為“不平衡”；keep in balance意為“保持平衡”；balance還作動詞，表示“（使）平衡；（使）均衡”。如： You must learn to keep your balance in skating. 在滑冰時你必須要學(xué)會保持平衡。,3. In recent years, tigers have been in danger of disappearing. 近年來，老虎已經(jīng)面臨消失的危險。 danger意為“危險”，通常是不可數(shù)名詞，表示做某事的危險或發(fā)生某情況的危險等，常用短語 be in danger (of)，意為“在危險中”。如： Is there any danger of fire? 有發(fā)生火災(zāi)的的危險嗎？,Exercises,1. _ (長頸鹿) are the tallest animals on land. 2. What beautiful _ (婚禮) clothes they are! 3. Uncle Yan visited many _ (亞洲的) countries last year. 4. He is interested in _ (歷史).,history,I. 根據(jù)句意及所給漢語提示，完成下列句子。,Giraffes,wedding,Asian,1. One of the world's biggest zoos _ (be) in Egypt. 2. My pet dog _ (die) two weeks ago. 3. _ (bar) keep the animals inside. 4. They got _ (marry) on August, 8th 2008. 5. The Siberian tiger is the _ (big) cat (貓科動物) in the world.,biggest,II. 用所給單詞的適當形式填空。,is,died,Bars,married,1. Nobody else wants to go to the village. (改為同義句) _ _ _ want to go to the village. 2. Liu Yang kept two dogs. (改為否定句) Liu Yang _ _ two dogs. 3. Those zoos have ten pandas. (改為同義句) _ _ ten pandas in those zoos.,There are,III. 句型轉(zhuǎn)換，每空一詞。,No other people,didn't keep,Homework,Work in groups and discuss some ways we can protect animals. Write down your ideas.,同學(xué)們,來學(xué)校和回家的路上要注意安全,同學(xué)們,來學(xué)校和回家的路上要注意安全,