1 . 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 people 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,the people 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 subjects read on the iPad as compared to the paper books,they reported feeling less sleepy at night and less active the following morning.People 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 gives 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.
1. In Charles Czeisler's experiment,all the subjects were asked to ______ .A.sit in a row and receive the strict tests |
B.have their sleep patterns observed all night |
C.read a paper book and an iPad at the same time |
D.have their blood tested per hour during the trial |
A.feel less sleepy and tired in the day |
B.fall asleep more easily after reading |
C.have a lot more melatonin secretion |
D.become less energetic the next morning |
A.remove the blue light from your devices completely |
B.help prevent eyes being harmed by short wavelength |
C.weaken the harm done by doing nighttime e-reading |
D.be used in all the e-things widely and safely |
A.No e-reading in bed before sleep |
B.New software for night e-readers |
C.Wrong behaviors before bedtime |
D.No games on iPad in bed. |
2 . Volunteering abroad is a great way to help others,improve your skills and become a more confident,independent person. If you are interested in volunteering abroad,here are some places to go.
Australia
If you seek a life on the beach,in a great climate with friendly people,Australia might be your best bet. With thousands of volunteers already signing up to leave for Australia during the holidays,it will be a very popular option.
Brazil
This vast country has some great opportunities on offer and is especially popular this year. A lot of volunteer work is available in Brazil centers on conservation and ecological projects. With the world's largest rainforest in Brazil,of which huge part is in danger,there are lots of different jobs you can do.
Kenya
Kenya is the destination for those seeking an African experience. Generally volunteers in Kenya work in orphanages (孤儿院) or with local children living in slums. There is a great demand for volunteers in Africa because many people live in poverty,so if you truly feel like making a difference to a community,Kenya should be at the top of your list.
Costa Rica
Golden sandy beaches,clear coastlines and beautiful cities are what Costa Rica is all about. Because of its small size,you can see a lot of the country in just a short time. You can really make the most of your time as a volunteer. A lot of work is needed with wildlife and ecological work,so if you want to look after turtles on the beach,Costa Rica could be just the place for you.
1. If you are interested in protecting the environment,you will probably go to .A.Australia | B.Brazil | C.Kenya | D.Costa Rica |
A.animals | B.plants | C.the elderly | D.children |
A.take care of trees in the forests | B.surf with children in the water |
C.work with animals on the beach | D.look after children who have lost their parents |