Unit 21
Lesson 1 Chewing gum
Warm-up
Teaching aims
1.    new words and phrases
2.     warm-up
3.     study the text: To chew or not to chew…
4.     grammar: conditionals
Teaching time
Two periods
Teaching process
Step 1 Revision:
1.    have a dictation (unit 20 new words)
2.    check homework exercises
Step 2 new words learning
1.ask some students to read the new words first and correct their pronunciation
2.play the tape and have them read after the tape
3.give them a few minutes to read the new words freely ,tell them if they can’t read the new words, encourage them to ask the teacher .
Step 3 Warm-up
1.Read unit objectives, and ask the students to tell us the meanings.
2.warm-up :Exercise 1
a)ask students read the key words first, then guess their meanings, have them translate the key words into Chinese.
b)students work individually, matching six of the key words with the numbers in the picture.
Then, check their answers.
c)ask them read the key words.
3.Exercise 2
a)     listen to the tape twice, have students guess which part of the body are being described.
b)     play the cassette ,pausing after each section to check their answers.
C )answers:1.brain 2.heart 3.hungs 4.eye 5.liver
4.Exercise 3
a)make sure the class know what to do. Then play the tape twice, ask some students to say their answers to the class.
5.Exercise 4:work in pairs and test your body “machine”
a)read out the instructions to the class and check that students understand them.
b)have the students work in pairs and discuss the questions.
6.exercise 4:give students a few minutes to do the questionnaire in pairs.
Then check their scores on page 103.
step 4 Reading
1.Before you start
a) read the exercise 1 and give them a few minutes to discuss the questions
b)ask some students to share their ideas with the class.
2.Read to learn
a)     ask the students look at exercise 2 and 3, and then play the cassette twice.
b)     give them ten minutes to read the text and complete the table.
c)     check theirs answers
3.exercise 4
a)     give students some time to do the exercises in pairs
b)     ask some students to answer the questions
4.Language points
a)Diet specialists regularly inform us that it is important to chew our food properly.
营养学家们经常告诫我们一定要正确咀嚼食物。
句型:It is +adj.+to do sth. It是形式主语,动词不定式是真正的主语.
b)it will help our bodies digest it better.这样才能有助于身体更好地消化食物.
help sb.do sth.
c)     does chewing gum have any effect on this process?咀嚼口香糖对这一过程有什么影响呢?
Have any effect on …
d)     one obvious benefit of chewing gum is that it fights bad breath.一个显而易见的好处是嚼口香糖能清除口腔异味.
That 引导的是表语从句.
Bad breath口腔异味
e)     if it has green plants materials added to it.
have sth. done.
Add to
f)     tooth decay 蛀牙
g)wash away清除
h)lose weight减肥
i)carry out进行,执行,开展
j)up to 一直到,等于
k)by now到如今
l)today, there are gum products that help smokers give up their bad habit.
That引导的定语从句修饰gum products,在从句中做主语.
Give up放弃
m)the negative side of
n)the production of stomach acid and digestive juices
o)it has also been proven that chewing gum for long periods of time means that the body does not have time to rest.
p)lead to
q)some…others….
r)send out v.发送, 派遣, 放出
s)instead of
t)brush one’s teeth
u)the number of …的数目；数量
v)on balance adv.总而言之
step 5 grammar: conditionals revision
1.exercise 6-9
read the instructions to the class. give them some time to do the exercises individually.
Then ask some students come to the blackboard to do them.
Step 6 Summary and homework
a)     summary b)
生词表: