The fact that blind people can see things using parts of their bodies apart from their eyes may help us to understand our feelings about color．If they can sense color differences, then perhaps we, too, are affected by color without knowing it．Salesmen have discovered by experience over a long period of time that sugar sells badly in green wrappings, that blue foods are considered not agreeable to the taste, and that cosmetics（化妆品） should never be packed in brown．These discoveries have grown into a whole subject of color psychology．
Some of our preferences are clearly psychological．Dark blue is the color of the night sky and therefore connected with calm, while yellow is a day color connected with energy and encouragement．Experiments have shown that colors, partly because they are connected with psychology, also have a direct effect on people's mind．People in bright red surroundings show an increase in breathing speed, heartbeat and blood pressure．Red is exciting．Pure blue has exactly the opposite effect; it is a calming color．Being exciting, red was chosen as the signal for danger, but a closer study shows that a bright yellow can produce a more basic state of alarm, so fire engines in some advanced areas are now rushing around in bright yellow colors that stop buses, trucks and cars．
The passage tells us that salesmen have____ ．

A．tried colors on blind people

B．found out that colors affect sales

C．developed a special subject of color psychology

D．discovered the relationship between color and psychology

It can be inferred from the passage that__ _．

A．blind people cannot sense color differences

B．foods sell well in green or blue wrappings

C．w hat color we prefer depends on our state of mind

D．a bright color has exactly the opposite effect to red

The most effective color in the passage for warning people is____．

A．red

B．dark blue

C．green

D．bright yellow

If someone is in an angry mood, which color is better for him to become quiet?

A．Red．

B．Dark blue．

C．Brown．

D．Bright yellow

Which of the following do you think is the best title for the passage?

A．Colors and Feelings

B．Colors and Sales

C．The Blind and Colors

D．Preferences for Colors