Unit 9 Text A Hothouse Effect
I. Teaching Objectives
1.Understand the audio materials of this unit.
2.Grasp the key words, Phrases and structure.
3.Master the skills of writing and reading in this unit.
1) Cause and effect
2) Modal word “would”, “should” and “might”
II. Teaching Content
2. Text Organization
3. Skill learning in writing and reading
4. Language points ( key words, phrases and difficult sentences)
5. Grammar Focus (1. “the more …the more…” 2. “while” )
6. Guided Practice (exercises, oral practice and group work)
III Teaching Process
1. Warm-up Questions / Activities
Text A discusses the “greenhouse effect” in which a buildup of certain chemicals in the earth’s
atmosphere threatens to create a disastrous increase in temperatures worldwide.
Work in small groups: discussing about “greenhouse effect in your daily life”
Share with the class.
Ask students to underline the sentences describing the weather
Ask students to underline the sentences showing the effect of the greenhouse on the industry
Check their work.
1).Looking at the title, what do you guess the passage is about? Make predictions, and then
read the first paragraph to find out what the “greenhouse effect” is.
2).In the discussion of the “greenhouse effect”, what do scientists disagree about? And, what
points do they agree on? Skim paragraphs 3 and 4 to look for your answers.
3).How serious of a threat do you consider the “greenhouse effect” to be? Give reasons for
This passage can be divided into 4 parts:
Part I. (Para1-3) Phenonenon: Carbon dioxide levels are on the rise. Part II: ( Para4-7) Causes: An
increasing amount of fossils are burned.
Part III. (Para8-9) Effects: Greenhouse effect. An increase of the earth’s temperature is sure to take
Part IV: ( Para10) Solutions: The greenhouse problem should be tackled now.
3. Skill learning in writing and reading
1). Reading skills: Cause and effect
This essay is primarily concerned with informing the reader about a number of possible results that might come from the greenhouse effect. This is an example of cause and effect writing, which makes clear the reasons why something happens by showing the connection between a cause (or causes) and its effect (or effects).
(1).For each of the causes below, put down the effect which is given in the essay.
a. cause: Global temperatures could rise 9 degrees over the next century.
effect: _______________________________________(Dangerous change to global weather patterns could be created.)
b. cause: Carbon dioxide in the atmosphere absorbs energy at infrared wavelengths.
effect: ______________________________________(The heat is kept from escaping and forms a “blanket” around the earth.)
c. cause: Temperatures have increased 1 degree over the last century.
effect: _______________________________________ (Many think that the greenhouse effect has already begun.)
d. cause: Mountain glaciers and polar ice caps might melt.
(The seas could rise and low-lying communities could be flooded.) (2).For each of the causes below, put down the effect which is given in the essay.
a. cause: _______________________________________
effect: Carbon dioxide builds up in the earth’s atmosphere.
(Fossil fuels are burned.)
b. cause: ________________________________________
effect: Some now-fertile areas could suffer droughts and some deserts could be irrigated.(Global rainfall patterns might shift.)
c. cause: ________________________________________
effect: Venus has a runaway greenhouse effect with temperatures approaching 900 degrees.(The atmosphere of Venus is about 97 % carbon dioxide.)(3).Because the evidence about the
greenhouse effect is still somewhat inconclusive, the author has to express a degree of uncertainty about the connections between their causes and effects. He do this by using modal verbs such as “could” and “would” and by using expressions such as “there is considerable debate” and “some scientists think.” With a partner, go over the text and underline all the modal verbs and other words or phrases which express a degree of uncertainty about future effects or about words or phrases which express a degree of uncertainty about future effects or about the connection between causes and effects. Explain what each one means in its context.
Examples of modals and modal-like expressions:
para. 2: ?could start to rise
?changes that could result
?could create dangerous changespara. 3:
?this forecast is somewhat uncertain
?there is considerable debate
?one thing seems certainpara. 5:
?could profoundly affectpara. 6:
?Some scientists think
2) Writing skill: Modal word
4. Language Points
1) hothouse n. a building, usu. with a glass roof and sides, kept warm for growing plants
1）hothouse flowers 2）hothouse production 3) hothouse /greenhouse effect 2) warn of / against — give a warning about e.g The computer expert warned the users against the visits from hackers.
3) result from — be the result of, happen because of
The quarrel between the two nations resulted in a bloody war.
4) rise vi.— (rose, risen, rising) to go, come up or higher; reach a higher level or position;
to get up from a lying, sitting, or kneeling position.
raise v.— (raised, raised, raising) to lift up;to cause to rise; to bring up for discussion or
attention; to breed or bring up.
— (arose, arisen, arising) come into existence; come to notice; present itself.
e.g. The horse rose on its hind legs.
The police raised a sunken ship to the surface of the sea
• Many problems arose when computers were firstly used in banking.
5) dry up — make or become completely dry
More phrases with “up”
beat up/ break up/ bring up/ brush up/ call up / choke up/ lear up/ draw up/ dress up/ wash up/
eat up/ hang up/ heat up/ hold up/ show up/ take up/
6) the more … the more … — used to show that the increase in one amount or degree of sth
continues at the same rate as another
Advice is like snow; the softer it falls, the longer it dwells up (驻留) the mind and the deeper it
sinks into the mind.
7) shut in — to keep, enclose
We are shut in by the hills here. 。 8) argue — give reasons to prove or try to prove
e.g. You can argue either way, for or against.
9) due to — because of, caused by
The team’s success was largely due to her efforts.
10) ups and downs — alternations of good and bad fortune, good and bad periods up and down — higher and lower; backwards and forwards, to and for
11) maintain — 1) continue to have, do, etc. as before
The improvement of her health is being maintained.
— 2) support with money
e.g. With a new-born baby, he’s under pressure to find a good job to maintain his family.
— 3) state as true, argue for (an opinion)
e.g. The accused official maintained that the mansion was a personal gift from a generous
12) explain away — to account, or give an excuse, for (something wrong)
The young man tried to explain away the missing money, but no one believed his story.
13) account for — serve as an explanation of
Please account for your disgraceful conduct.
14) keep an eye on — (fig.) keep a watch on
e.g. The retired professor keeps an eye on the latest development in his field.
5. Grammar focus:
Could as a possible alternative to may / might
1). Call Ss’ attention to the following sentences in the text:
The increased carbon dioxide could profoundly affect the way the earth is heated by the sun,
Others argue that the rise could be due to natural temperature ups and downs.
2) When we want to say there is a chance that something will happen, we usually use may or
e.g — Do you think the train will be on time?
— I don’t know. It may/ might/ could be delayed by fog. ]
Could, however, is used to give the idea that something is just possible, but not particularly
likely, as in the above sentences.
e.g We could go swimming this afternoon, but I doubt if we’ll haave time.
It could snow later on this evening. 6. Guided Practice (exercises, oral practice and group work)
A. Ask students to retell the text by using their own words.
B. Talk about the main idea or theme of the text.
A. Comprehension of the text(During the period of preview or discussions in class).
B. vocabulary IV--VII(homework)
C. Translation( on exercise-book)
7. After-class Assignments
1). Do Exs P246-254
2). Write a short passage in which you describe the effect (or effects) that this change would have
on your life if it should happen to you. Use the modal verbs, might, could, and should to
express the ideas of possibility, likelihood, and advisability. Use would to express what you
feel you would actually do.
Text B The population problem: Everybody’s Baby
1. by 1930 world population stood at 2 billion ------ by 1930 world population had reached 2
2. population growth goes way ahead of the gains in food production ------ population grows
at a much greater speed than does food production
3. The probability of accomplishing such goals is not high, given the uncertainties of
weather and the difficulty of raising sufficient capital to finance such efforts. ------ If we
enough funds, it is not very likely that we will be able to accomplish such goals.
4. to say nothing of billions more ------ without even considering the billions more people who take into account the uncertainties of weather and the difficulty of raising
will populate earth in the future
5. they have paid a price in increasing irritability and feelings of alienation ------ they have
suffered from increasing irritability and feelings of alienation as a result of the crowded living
conditions in huge cities.
6. One doesn’t need a crystal ball to find the answer. ------ The answer is plain enough for
people to see for themselves; we don’t need a fortune-teller to tell us what is going to hppen.