US scientists say they have poured cold water on the theory that washing hands with hot water kills more germs (细菌) than unheated water. The small study of 20 people found using water at 15C (59F) left hands as clean as water heated to 38C (100F).

    National Health Service (NHS) recommends that people wash their hands in either cold or warm water. In this study, scientists at Rutgers University-New Brunswick wanted to find out if popular assumptions about the benefits of warm or hot water and official guidance on hot water — given to the food industry in the US — held true. They asked 20 people to wash their hands 20 times each with water that was 15C (59F), 26C (79F) or 38 degrees (100F). Volunteers were also asked to experiment with varying amounts of soap. Before they started the tests, their hands were covered in harmless bugs. Researchers say there was no difference in the amount of bugs removed as the temperature of the water or the amount of soap changed.

    Prof Donald Schaffner said: “People need to feel comfortable when they are washing their hands but as far as effectiveness goes, this study shows us that the temperature of the water used did not matter.”

    However, the researchers accept their study is small and say more extensive work is needed to determine the best ways to remove harmful bacteria.

    In the UK, NHS experts say people can use cold or hot water to wash their hands. They say hands should be washed for at least 20 seconds and stress the importance of using enough soap to cover the whole surface of the hands. Their guidance focuses on rubbing hands together in various ways to make sure each surface of each hand is clean.

发展高新技术产业依赖的主要条件是（　　）

    Are you suffering from FOMO—that is, Fear Of Missing Out? Research shows that a growing number of young people are, with worrying consequences for their sleep and schoolwork.

    ____You aren't able to do your best unless you sleep well. Most experts agree that the optimum(最适宜) number of hours is eight, and this has been accepted as common sense for as long as I can remember. However, I was young once and know most of you get much less sleep than that.

    I read an interesting article in a teachers' magazine recently.____Worryingly, the results showed that teenagers are facing a new problem. They may go to bed and get up at appropriate times, but a growing number are waking up in the middle of the night, not to use the bathroom or have a snack, but because of FOMO.

    According to the article, the number of students waking up during the night to check social media is growing. Afraid of missing a comment or opportunity to take part in a chat, teenagers are waking at all times of the night, going online and getting involved.____

    Experts are worried about this growing trend and the report reveals some worrying statistics: 23% of 12-to 15-year-olds wake up nearly every night to use social media.____One in third of the students are constantly tired and unable to function to their full capacity.

    So I'd like to ask you to be responsible when it comes to social media. Switch off your devices at night. The world won't end and your social media will be waiting to greet you in the morning!____

A.But things are getting out of hand.

B.They did a study of 848 students in Wales.

C.Another 15% wake up at night once a week for the same reason.

D.I give you my word that you won't have missed anything important.

E.All happens when they should be sound asleep.

F.FOMO is the fear that everyone else is having more fun and more excitement than you.

G.Everybody knows how important it is for students to get a good night's sleep every night.