[单项选择]Why does the author give some examples of bad rules
A. Because those rules are said to be strongly negative.
B. Because he wants to show that rules are not the criteria for judging right or wrong.
C. Because those rules are made in order to stop what is wrong.
D. Because he wants to support the argument that stealing a book is not a crime.

[单项选择]

Why does cream go bad faster than butter Some researchers think they have the answer, and it comes down to the structure of the food, not its chemical composition — a finding that could help rid some processed foods of chemical preservatives.
Cream and butter contain pretty much the same substances, so why cream should sour much faster has been a mystery. Both are emulsions — tiny globules (小球) of one liquid evenly distributed throughout another. The difference lies in what’s in the globules and what’s in the surrounding liquid, says Brocklehurst, who led the investigation.
In cream, fatty globules drift about in a sea of water. In butter, globules of a watery solution are locked away in a sea of fat. The bacteria which make the food go bad prefer to live in the watery regions of the mixture. "This means that in cream, the bacteria are free to grow throughout the mixture," he says.
When the situation is reversed, the bact
A. it suggested a way to keep some foods fresh without preservatives
B. it discovered tiny globules in both cream and butter
C. it revealed the secret of how bacteria multiply in cream and butter
D. it found that cream and butter share the same chemical composition

[单项选择]What does the author mean by giving the examples of the US and the Sahara Desert in Paragraph Two
A. The US is the wealthiest country in the world while the Sahara Desert is the poorest region.
B. Some regions of the world are well supplied with natural resources while other regions possess none of them.
C. Some countries can better use natural resources while other countries have been unable to develop their resources.
D. The US has a sound and stable political condition while the Sahara Desert has suffered for many years from civil wars.

[单项选择]Why does the author give a detailed description of U.S. aid workers
A. Because they set up a field hospital for the Iran people.
B. Because the U.S. medical team is composed of the best doctors.
C. Because they are the ones that have received the warmest welcome.
D. Because U.S. has had no dealings with Iran since 1979.

[单项选择]Why does the author give the example of the terrorist attack on Sept.11
A. To prove that human is at risk.
B. To demonstrate that mankind is more nervous than any other time.
C. To show that anxiety seldom reoccurs.
D. To indicate that anxiety is easy to arouse.

[单项选择]Why does the author give his opinion of the definition of poetry

[单项选择]Why does the author give an example in the last paragraph


A. To show how a smuggler is caught.
B. To show a smuggler is afraid of the police.
C. To show to keep a wary eye on couriers is useless.
D. To show mules may keep the profit for themselves.

[单项选择]Why does the man want to give her daughter a history book

[单项选择]Why does the author suggest that some people are urged to defer in discussions of international research
A. Because there is a lack of equality between the relevant parties.
B. Because of pressure from the local communities.
C. Because of pressure from the international community.
D. Because there is a temptation to think in their own favor.

[单项选择]Why does the author suggest that some leaders of the new economy say they are not in business for the purpose of making money