Using a computer or smartphone at night can cause us to pile on the pounds，new research has revealed．
The study found a link between blue light exposure(blue light is produced by smartphones and computers)and increased hunger．It found that exposure to blue light increases hunger levels for several hours and even increases hunger levels after eating a meal．Blue light exposure has also already been shown to cause decreased  sleepiness in the evening，increasing the risk of sleeplessness．
The leading researcher，Ivy Cheung，from Northwestern University in Chicago，said，“A single three-hour exposure to blue-enriched light in the evening greatly affected hunger and metabolism(新陈代谢)．These results are important because they suggest that controlling environmental light exposure for humans may represent a novel approach of influencing food intake patterns and metabolism．”
The study group consisted of 10 healthy adults with regular sleep and eating schedules. They completed a four-day trial under dim(昏暗的)light conditions，which involved exposure to less than 20 lux(勒克斯，照明单位)during 16 hours awake and less than 3 lux during eight hours of sleep．On the third day they were exposed to three hours of 260 lux，blue-enriched light starting10.5 hours after waking up．and the effects were compared with dim light exposure.
Ivy Cheung said more research is needed to determine the functions involved in the relationship between light exposure，hunger and metabolism．
What is Paragraph 2 mainly about?

A．How blue light exposure affects hunger．

B．Why blue light exposure influences sleepiness．

C．What is the link between blue light exposure，hunger and sleepiness．

D．Who has found the effects of blue light exposure on hunger and sleepiness．

The underlined word“novel”in the third paragraph probably means“___________”.

A．unusual	B．unforgettable
C．temporary	D．controversial

What can we learn from the passage?

A．Blue light exposure can make us lose weight at night．

B．Blue light exposure has no effect on sleeplessness．

C．The researchers drew their conclusion by comparison．

D．Ivy Cheung has found the relationship between light exposure and hunger．

Where would you be most likely to find the passage?

A．On a notice board．	B．In a health magazine．
C．On a business website．	D．In a college newspaper．