1、Unit 21 Human Biology,Lesson 1 Chewing Gum,Warm-up,Exercise 1 Read the Key Words and then label the parts of the body in the diagram,ankle, brain, eye, heart, kidneys, bone, knee, liver, lungs, muscle, ribs, skin, Spine, stomach, wrist, fingers,Answers: 1.brain 2.lungs 3.heart 4.liver 5.stomach 6.ki

2、dneys,Exercise 2 Listen and guess which part of the body are Being described.,Answers: 1.brain 2.heart 3.lungs 4.eye 5.liver,Exercise 3 work in pairs and test your body “machine”,Memory.,Hearing.,Heart.,Write down five telephone numbers and give them to your partner to look at for 30 seconds. How ma

3、ny can he/she remember?,Everybody in the class sits in silence for 30 seconds. Write down every sound you can hear. Compare your list with your partner.,Find the pulse on your partners wrist. How many times does his/her heart beat in one minute? Is he/she more or less relaxed than you?,exercise 4:gi

4、ve students a few minutes to do the questionnaire in pairs. Then check their scores on page 103.,1.How many hours do you sleep per night? a)under 6 hours b)about 7 or 8 hours c)more than 9 hours 2.How often do you clean your teech? a)once a day b)twice a day c)after every meal 3.How often do you do

5、physical exercise, enough to make you out of breath? a)never b)once a week c)two or three times a week 4.How often do you eat sweets or chocolate? a)never b)sometimes c)every day 5)How many pieces of fresh fruit do you eat per day? a)one or two b)more than two c)none,Lesson 1 Chewing Gum,Exercise1 d

6、iscuss in pairs and answer the following questions,1.What do you think of chewing gum? is it good or bad for you? 2.Do you or your friends/family buy it? why? 3.What do you do after chewing it?,Exercise 2 look at the title of the magazine artricle and predict which issues may be covered in the artic

7、le. Then read the article quickly and see if any of your guesses are right.,Exercise 3 complete the table:,Exercise 4 answer the questions,1.How serious is the problem of bad breath? 2.What is added to sugar-free chewing gum which may help prevent tooth problems? 3.According to one research project,

8、 what is one way of burning 70 kilocalories? 4.What would be the effect on the stomach of constant chewing? 5.What other activities are stated that are better than chewing gum?,It is a problem for 50% of the worlds population.,Chlorophyll,Chewing 100 times per minute for 12 minutes.,The stomach may

9、become strained and eventually this could lead to stomach irritations or ulcers.,Brush teeth regularly,eat healthy foods avoiding sugar, never start smoking, and chew a mint leaf.,Language points,1) Diet specialists regularly inform us that it is important to chew our food properly. 營養(yǎng)學(xué)家們經(jīng)常告誡我們一定要正確

10、咀嚼食物。 句型:It is +adj.+to do sth. It是形式主語,動詞不定式是真正的主語. 2) it will help our bodies digest it better. 這樣才能有助于身體更好地消化食物. help sb.do sth. 3) does chewing gum have any effect on this process? 咀嚼口香糖對這一過程有什么影響呢? Have any effect on ,4) one obvious benefit of chewing gum is that it fights bad breath. 一個顯而易見的好處

11、是嚼口香糖能清除口腔異味. that 引導(dǎo)的是表語從句. bad breath口腔異味 5) if it has green plants materials added to it. have sth done. add to 6) tooth decay 蛀牙 7) wash away清除,8)lose weight減肥 9)carry out進(jìn)行,執(zhí)行,開展 10)up to 一直到,等于 11)by now到如今 12)today,there are gum products that help smokers give up their bad habit. that引導(dǎo)的定語從句修

12、飾gum products,在從句中作主語. give up放棄,13)the negative side of 14)the production of stomach acid and digestive juices 15)it has also been proven that chewing gum for long periods of time means that the body does not have time to rest. 第一個that引導(dǎo)的賓語從句，作proven的賓語 第二個that引導(dǎo)也是賓語從句，作means的賓語 16)lead to 17)someo

13、thers.,18)send out v.發(fā)送, 派遣, 放出 19)instead of 代替 20)brush ones teeth 刷牙 21)the number of 的數(shù)目；數(shù)量 22)on balance adv.總而言之,grammar,conditionals revision,Exercise 6 match the conditional sentences in italics in the text with the following types:,Zero conditional 1st conditional 2nd conditional 3rd condit

14、ional Which of the sentences in italics talk about the past, the present and the future?,1.They suggest that if we chew our food until it is soft in our mouths and then swallow it , it will help pur bodies digest it better. 2.According to some doctors, if these people were to chew sugar-free gum, it

15、 would help fight this embarrassing condition. 3.Recently ,some dentists have also claimed that sugar-free gum, if it has green plants materials added to it, helps to stop tooth decay. 4.therefore, they say, if people were to chew sugar-free gum after a meal, it would help prevent tooth trouble. 5.F

16、urther research has been carried out, which shows that, if you had chewed sugar-free gum regularly for the last year,it is possible that you would have lost up to 5 kilos by now.,1st conditional ,future,2st conditional ,future,zero conditional ,present,2st conditional ,future,3st conditional ,past,6

17、.They found if people chewed 100 times per minute for 12 minutes,70 kilocalories were burned. 7.One former smoker has appeared in an ad. Saying,”if I had used this chewing gum when I was giving up smoking ten years ago, I would have been more successful at quitting quickly and much healthier today.”

18、 8. If we chew gum, it will cause our bodies to believe we are digesting food and our stomachs will produce digestive juices unnecessarily. 9. If this is the case, the stomach may become tense. 10.They argued that if dentists encouraged its use, the wrong message would be sent out and children might

19、 chew gum instead of brushing their teeth. 11. Unless we are careful, the number of young people with bad teeth will rise and this will become a serious problem.,2st conditional ,present,1st conditional ,future,3st conditional ,past,zero conditional ,present,2st conditional ,future,1st conditional ,future,Exercise 7 read the sentences. Do they describ