题目内容：

Some colors people see late at night could cause signs of the condition mental health experts call clinical depression(临床抑郁症). That was the finding of a study that builds on earlier study findings. They show that individuals who live or work in low levels of light overnight can develop clinical depression.

Doctors use the word clinical depression to describe severe form of depression. Signs may include loss of interest or pleasure in most activities, low energy levels and thoughts of death or suicide.

In the new study, American investigators designed an experiment that exposed hamsters（仓鼠）to different colors. The researchers chose hamsters because they are nocturnal, which means they sleep during the day and are active at night. The animals were separated into four groups. One group of hamsters was kept in the dark during their night-time period. Another group was placed in front of a blue light, a third group slept in front of a white light, while a fourth was put in front of a red light. After four weeks, the researchers noted how much sugary water the hamsters drank. They found that the most depressed animals drank the least amount of water.

Randy Nelson, at Ohio State University, says animals that slept in blue and white light appeared to be the most depressed. “What we saw is that these animals didn’t show any sleep interruptions at all but they did mess up biological clock (生物钟) genes and they did show depressive sign but if they were in the dim red light, they did not.” He says there’s a lot of blue in white light. This explains why the blue light and white light hamsters appear to be more depressed than the hamsters seeing red light or darkness.

1. From the text we know that ________ made the hamster feel depressed.

A. the amount of the water      B. the colour of the light

C. the loss of pleasure         D. the level of energy

2.What was the purpose of the experiment on hamsters?

A. To show how well they slept.

B. To see how much sugary water they drank.

C. To explain why they liked dark colours.

D. To find out what caused the depression on them.

3. The author explains the clinical depression by _________.

A. reporting an experiment process

B. presenting research data

C. setting down general rules

D. giving his own experience

4.Where can we probably find the text?

A. In a science magazine.

B. In a physics textbook

C. In a tourist guidebook.

D. In an official announcement.