Identifying reasons

This exercise also gives you practice in assessing what could count as a reason for a given
‘conclusion’. In each question, pick the answer which could be a reason for the conclusion,
and say why this is the right answer, and why the other options are wrong. Note that you
are not to worry about whether the reason is true. You must just consider whether, if it
were true, it would support the conclusion.
1 Conclusion: Blood donors should be paid for giving blood.
(a) The Blood Donor service is expensive to administer.
(b) People who give blood usually do so because they want to help others.
(c) There is a shortage of blood donors, and payment would encourage more people
to become donors.
2 Conclusion: When choosing someone for a job, employers should base their decision
on the applicants’ personalities, rather than on their skills.
(a) Personalities may change over time, and skills go out of date.
(b) Skills can easily be taught, but personalities are difficult to change.
(c) Some skills cannot be acquired by everyone, but everyone can develop a good
personality.
3 Conclusion: Light-skinned people should avoid exposure to the sun.
(a) Ultra-violet light from the sun can cause skin cancer on light skins.
(b) Dark-skinned people do not suffer as a result of exposure to the sun.
(c) Light-skinned people can use sun creams in order to avoid sunburn.
4 Conclusion: Installing insulation in your house may be economical in the long run.
(a) Less fuel is needed to heat a house which has been insulated.
(b) In a house which has been insulated the air feels warmer.
(c) Some types of insulation cause houses to be damp.
5 Conclusion: In order to reduce crime, we should not use imprisonment as a punishment
for young offenders.
(a) Young offenders could be taught job skills whilst in prison.
(b) It would be expensive to build new prisons to relieve prison overcrowding.
(c) Young offenders are more likely to re-offend if their punishment has been a
term of imprisonment.
6 Conclusion: Sam could not have committed the murder.
(a) Sally had both the opportunity and a motive to commit the murder.
(b) Sam could not have gained anything by committing the murder.
(c) Sam was several miles away from the scene of the murder when the victim was
stabbed to death.
7 Conclusion: A vegetarian diet may be beneficial to health.
(a) A vegetarian diet lacks certain important vitamins.
(b) A vegetarian diet excludes animal fats which can cause heart disease.
(c) A vegetarian diet excludes fish oil which is thought to be beneficial to health.
8 Conclusion: Parents should be strongly advised to have their children vaccinated
against polio.
(a) Some parents think that there is a risk of harmful side effects from the polio
vaccine.
(b) If a substantial percentage of the population is not vaccinated against polio,
there will be outbreaks of the disease every few years.
(c) The risk of becoming infected with polio is very low.
9 Conclusion: Those people who die from drowning are more likely to be swimmers
than to be non-swimmers.
(a) People who cannot swim are much more likely than swimmers to avoid risky
water sports.
(b) Many deaths from drowning occur because people on boating holidays fail to
wear life-jackets.
(c) Even those who can swim may panic if they fall into the sea or a river.
10 Conclusion: Some types of chewing-gum are bad for the teeth.
(a) Some chewing-gums are sweetened with sorbitol, which helps to neutralise
tooth-rotting acids.
(b) The action of chewing gum can get rid of particles of sugar trapped between the
teeth.
(c) Some chewing-gums are sweetened with sugar, which causes tooth decay.
11 Conclusion: A worldwide epidemic amongst humans of the H5N1 strain of bird flu is
unlikely to occur.
(a) People can catch the H5N1 strain of bird flu from contact with infected birds.
(b) The H5N1 strain of bird flu cannot be transmitted easily between people.
(c) Scientists are working on the development of a vaccine against the H5N1 strain
of bird flu.
12 Conclusion: Studies of the effects of diet on health which rely on people reporting
everything they have eaten may give inaccurate results.
(a) Some people in the study may not enjoy eating healthy foods.
(b) Some people in the study may not remember what they have eaten.
(c) Some people in the study may have been unhealthy when the study began.
13 Conclusion: If you want to save electricity, you should switch the light off whenever a
room is unoccupied for however short a time.
(a) Turning a light on and off frequently has no damaging effect on the bulb.
(b) Using less electricity saves you money and reduces carbon emissions.
(c) Starting up a light requires very little electrical power.
14 Conclusion: Playing computer games can be beneficial for children.
(a) Children who play computer games are less interested in reading.
(b) The visual skills of children improve when they first start playing computer
games.
(c) Watching television is no more educational for children than playing computer
games.
15 Conclusion: The fall in the percentage of married couples who divorce in the UK is
not evidence that the percentage of unloving marriages has fallen.
(a) The total number of marriages per year in the UK has been steadily
falling.
(b) People who live together without marrying are more likely to split up than those
who are married.
(c) Some couples remain married simply because divorce is regarded as too
expensive.