The bed should be reserved as a place for sleep, but people tend to read an iPad a lot in bed before they go to sleep.
Charles Czeisler, a professor at Harvard Medical School, and his colleagues got a small group of people for an experiment. For five days in a row, the subjects (实验对象) read either a paper book or an iPad for four hours before sleep. Their sleep patterns were monitored all night. Before and after each trial period, they took hourly blood tests to paint a day-long picture of just how much melatonin (褪黑激素) was in their blood at any given time.
When the subjects read on the iPad as compared to the paper books, they reported feeling less sleepy at night and less active the following morning. They also took longer to fall asleep on the iPad nights, and the blood tests showed that their melatonin secretion (分泌) was delayed by an hour and a half.
The researchers conclude in today's journal article that given (考虑到)the rise of e-readers and the increasingly widespread use of e-things among children and adolescents, more research into the long-term consequences of these devices on health and safety is urgently needed. Czeisler and colleagues go on, in the research paper, to note：“Reading an iPad in bed may increase cancer risk.”
However, software has been developed that can reduce some of the blue light from the screens of phones and computers according to time of day, and there are also glasses that are made to filter (过滤) short wavelengths. While they seem like a logical solution for the nighttime tech users, it needs more research.
In Charles Czeislers experiment, all the subjects were asked to______.

A．sit in a row and receive the strict tests

B．have their blood tested per hour during the trial

C．read a paper book and an iPad at the same time

D．have their sleep patterns observed all night

The third paragraph tells us the iPad readers were likely to______.

A．feel less sleepy and tired in the day

B．become less energetic the next morning

C．have a lot more melatonin secretion

D．fall asleep more easily after reading

The special software recently developed can______.

A．weaken the harm done by doing nighttime e-reading

B．help prevent eyes being harmed by short wavelength

C．remove the blue light from your devices completely

D．be used in all the e-things widely and safely

Which title is the best one for the text?

A．Wrong behaviors before bedtime

B．New software for night e-readers

C．No e-reading in bed before sleep

D．No games on iPad in bed