Cracking the toefl ibt 2008 part 23

236 ME CRACKING THE TOEFL nicotine adrenaline... Female Professor: Okay, | know from having taught this class before that the topic I'm about to cover has the potential to get peaple's

instructions?

(A) He cannot get in contact with her doctor

(B) She hasn't been on her special diet long enough

(C) He hasn't received her file yet

(D) He hasn't observed her symptoms

3 Why is the elimination test more difficult? —

(A) It must be performed at the student health center

(B) There is more danger of a serious reaction

(C) It takes more time and effort

(D) {t requires injections

4 When can the spot test described by the man be

used?

(A) When the elimination test did not produce results (B) When the symptoms are becoming worse over time (C) When the patient has too little time for the elimination test (D) When the doctor has some idea of the cause of the allergy

5 What will the woman do next?

(A) Get her file from the student health center (B) Tell the man when she can meet next (C) Tell the man what she has eaten lately (D) Start the diet for the elimination test

234 ME CRACKING THE TOEFL

DRILL #3: A LECTURE

Have a friend read the following lecture from.a biology class: The professor is discussing the physical

effects of smoking, This transcript is similar to lectures that you'll hear on the TOEFL Answer the

questions that follow the transcript

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236 ME CRACKING THE TOEFL

nicotine

adrenaline

Female Professor: Okay, | know from having taught this class before that the topic I'm about

to cover has the potential to get peaple's blood boiling, so I'd like to start off by making something clear: I'm going to discuss the physical effects of tobacco

on the body This is not the place for a debate over social issues If you all want to get into it over lunch after class is over, you’re- welcome to, Just don't

expect me to join in

Anyway, what we want to talk about is what happens to your body when you

smioke or chew tobacco The- primary active ingredient in tobacco is one

you're probably all familiar with: nicotine Nicotine isa class of chemical called

an alkaloid, meaning that it's a close relative of the caffeine in cottee and the

natural drugs found in some plants, it generally has a stimulant effect—it gets

your body systems going, makes them more active It actually makes up a very small percent of the tobacco plant—about 5 percent by mass—not much, right? Also, when you smoke tobacco, most of the nicotine burns away before you can éven inhale it That means that most of the nicotine in your cigarettes never gets to your lungs It’s not ingested, So between those two things—the

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238 ME CRACKING THE TOEFL

low proportion of nicotine in the tobacco plant, and the high proportion of the nicotine that's destroyed before you ingest it—you're not really getting a whole lot with each puff

Even so, the nicotine in cigarettes has a powerful effect on the body for a few reasons For one thing, while some drugs pass through the body largely without being absorbed, nicotine inhaled into the lungs is absorbed almost completely This is because the lungs have a lot of surface area that's usually used to exchange oxygen and carbon dioxide when you breathe All that surface area provides lots and lots of places for nicotine to pass into the bloodstream Then there’s the fact that nicotine crosses the blood-brain barrier quickly The blood-brain barrier is a sort of gatekeeping system in the

bloodstream It severely limits the ability of substances and organisms to pass

from the blood into the brain This helps keep the chemical environment of the

brain stable, which it needs to function properly, and it also keeps the brain clean you know, nasty infections can't get in, even if the rest of the body is

sick fighting them off

Because nicotine is one of those chemicals that crosses the blood-brain

barrier quickly, it affects the nervous system right from its command center

And it has two big effects One is that it stimulates the production of the hormone adrenaline More adrenaline means an increase in your heartbeat, your breathing, and possibly even cognition—that is, the thinking and perceiving nerves in your brain That would help right? to explain why

people report feeling energized and sharper, more aware, after smoking a

cigarette Their breathing and heart rates are jazzed up, and their thinking

nerves are too

You may be thinking at this point, Well, that’s how people get addicted to smoking—it makes them feel more energetic and stuff, and you're partially right, but there’s another physiological reason Scientists have evidence that nicotine stimulates the production of not only adrenaline but also another chemical: dopamine Levels of dopamine rise when you're doing something enjoyable, like eating your favorite food So what happens is some

researchers refer to it as a reinforcement or reward mechanism Dopamine signals well-being, so when nicotine stimulates dopamine production, it’s kind of like exciting your pleasure center That's probably the source of the rush people associate with smoking, and why they keep reaching for more

cigarettes to get that same feeling again after it passes

Now, those are the most obvious direct affects, but nicotine alters body

functions in other ways that are also significant For instance, it decreases the amount of oxygen that gets to the brain, which can make you feel more relaxed It also, at least in the short term, relaxes the stomach In fact—some

of you may know this, but—nicotine used to be prescribed as medicine for these reasons Doctors would tell people to use tobacco if they were nervous

or anxious because the nicotine calmed them down Likewise, people with upset stomachs would be told to use nicotine because the relaxing effect on the stomach helped digestion Now, the problem—the biggest problem—is that these are short-term effects, but as you continue to use nicotine a lot over

a period of time, it has bad effects that aren't immediately obvious Nicotine can cause stomach ulcers and make heari problems worse You may get short-term relief, but you'll eventually be worse off

Now, ask one of your friends to repeat the part of the lecture below, which is what the actual

TOEFL will do

Okay, | know from having taught this class before that the topic I’m about to cover has the potential to get people's blood boiling, so I'd like to start off by making something clear: I'm going to discuss the physical effects.of tobacco

on the body This is not the place for a debate over social issues

1 Listen again to part of the discussion Then answer

the question

What can be inferred about the professor? GS

(A)

(B) (C)

(D)

She is not used to teaching students about the effects of

tobacco

She thinks the topic may be confusing

She wants to avoid a controversial discussion

She thinks the debate over tobacco is interesting

2 Why is only a small amount of nicotine ingested in

smoking?

(A)

(B) (C) (D)

The processing of tobacco removes a lot of nicotine,

The body does not abserb nicotine easily

Most of the nicotine is destroyed by burning

The tobacco plant contains little nicotine,

3 Why does nicotine affect the nervous system

powerfully?

(A) (B)

(C)

(D)

The brain has a large surface area

Nicotine is sirnilar In structure to some hormones

Blood travels directly from the lungs to the brain

Nicotine crosses the blood-brain barrier quickly

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4 What effect does adrenaline have on people's moods?

(A) They feel more alert

(B) They feel calmer

(C) They become more nervous

(D) They think more slowly and carefully

5 How does dopamine contribute to cigarette addiction?

(A) It makes people more energetic

(B) It sends signals associated with pleasure

(C) It decreases the amount of oxygen to the brain

(D) Itlowers heart and breathing rates ~-

6 What kinds of illnesses used to be treated with tobacco?

(A) Heart disease

(B) Anxiety

(C) Poor digestion (D) Breathing problems

240 Mi CRACKING THE TOEFL

LECTU

DRILL #4: A

Listen fo Track 3 on th e CD-ROM et the foll owing q uesti

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ING

LISTEN

242 ME CRACKING THE TOEFL

ectomorphic esomorphic endomorphic

1, Whatis the lecture mainly about?

- (A) The layers ‘of the humen body

(B) Away of categorizing peaple’s personalities (C) The best kind of exercise for differerit body types (D) How:students can identify their own body types

2 What do biologists use to divide the body into

layers?

(A) The amount of fat in each type of tissue

(B) The origins of the different cells

(C) The type of personality in which each area js dominant (D) The kind of activity with which the tissues are associated

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