Is human blood all the same? “Yes，” you may say．“It's all red．”

Well，it's not as simple as you might think．

Blood is made up of different parts，such as red blood cells，white blood cells，and platelets（血小板）．

Two chemical molecules（分子）on the red blood cells make people's blood different．Scientists mark one molecule "A" and the other molecule "B".

According to which and how many molecules are on the red cell, scientists divide blood into four types: A, B, AB and O.

Your blood type will stay the same your whole life.

Scientists have been wondering if there are some links between people's blood type and their personalities but they don't know for sure yet.

  But some say that people with the same blood type may have things in common.

What's your blood type? Do you have family members or friends who are the same type as you? Read the following. Are you like this?

People with type A: They look peaceful from the outside. But they ask too much of themselves that they may be very nervous inside. They get happy or sad easily. Sometimes they are shy but always very careful. They can easily win people's trust.

People with type B: They have strong minds. Once they start a task, they don't give up easily. They'll try their best to finish it and do it well. Type B people always try to make themselves different from others. They want to do things in their own way in life.

People with type AB: They are maybe the strangest among all blood types. They can be both open and shy, noisy and quiet at the same time! They are responsible （负责的） and always ready to help others.

People with type O: They're open and good at making friends. They always start tasks but don't always finish them. They have lots of new ideas and love to be the centre of attention. They always strongly believe in themselves.

1. What's the main subject of this passage?

A．blood types                                      B．blood types and personalities

C．personalities                                      D．scientific research on blood

2. The blood types are decided by ____________.

A．the amount of white blood cells

B．the amount of platelets

C．the kind and amount of molecules on the red cell

D．the kind and amount of molecules on the white cell

3. Scientists are ________ about the relation between blood types and personalities.

A．not sure                    B．quite sure            C．excited               D．worried

4. If a person always tries to be different from others, he/she might have _________ blood.

A．A type               B．B type                C．AB type              D．O type

5. Which of the following is NOT true according to the passage?

A．A person's blood type will never change throughout his life.

B．A person's blood type might have something to do with his/her personality.

C．A person with type O blood is usually confident.

D．A person with type A blood has the strangest personality.

In the West, some people believe that personality can be predicted according to the time of the year the person was bor. From China comes the belief that the year of birth influences one’s personality. In the past century, a new belief ahs arisen: the idea that personality is related to one’s ABO blood type. People with blood type A, for example, are considered more likely to be serious, hard-working, and quiet, while people with blood type O are likely to be popular and outgoing, yet often unable to finish what they start. Though this belief continues to be strong, some people question whether it is true.
The blood-type personality theory(理论) started in Japan in 1927 when Furukawa Takehi noticed personality similarities and differences among his workers. This idea soon went out of fashion, but was brought back by a Japanese television host named Toshitaka Nomi in the 1970s. The belief is still strong in Japan and is increasingly popular in neighboring countries. Some young Koreans have taken to the theory. A recent study showed 76 percent of Koreans aged between13 and 64 believing in the blood-type personality connection. Though most Asians might believe in the blood-type theory, for many it seems harmless and not something to be taken too seriously.
Is the belief true? The scientists in Asia largely think the belief as a modern-day superstition(迷信). Most studies have failed to find any strong connection between blood and personality. Generally, scientists are against making predictions or important decisions based on this questionable theory.
【小题1】The writer uses blood type A and O as an example to explain ________.