Do equations and historical( 历史的) facts give you a headache? A change in the school timetable(课程表) may be the cure.

    This  suggestion  is  based  on  a  recent  study  carried  out  by  scientists  from  Royal  Holloway, University of London, the UK. They found that teenagers could get higher marks in math if they studied in the mornings and better grades in history if they were taught in the afternoons.

    The researchers studied students' grade reports, class timetables and absence rates( 缺席率) at a middle school in Bulgaria over nine years. The results showed that when teenagers had math classes earlier in the day, they scored about 7 percent higher in tests than when taught in the afternoon. Lower-ability students feel stressed most when they were studying math in the afternoon. In history, students taught in the afternoon scored about 6 percent higher than when they were taught in the morning. However, there was no sign that similar patterns( 模 式 ) work for other subjects such as languages or geography.

    Velichka Dimitrova, who did the study, said the findings show that we perform( 表 现 ) better at different times of the day. “In the morning, our brains are better and fresher, so we are better at doing something like problem solving, where we require more speed and attention” Dimitrova told The Telegraph. “In the afternoon, it seems that this process slows down. On the other hand, history is more suitable for the afternoon, when we are more creative and open to discussion,” she said. Subjects such as foreign languages require both memory and creativity. This is perhaps why the time of day had no influence on language learning.

    Time-of-day influences such as these are believed to have something to do with the body clock.

    This is the system in our bodies that controls when we need to sleep. Some schools in the US and UK have tried later school starting times for teenagers, whose body clocks change as they grow into adults. Dimitrova believes schools should jump at this chance to improve their students' performance just by changing their timetables.

    The Internet joins millions of computers all over the world,and today it is used by people all over the world.It was invented in the 1960s in the USA.The American government needed a network of computers for its army.Then in the 1970s scientists and business people also wanted to use the Internet to send and receive messages.For some years,they weren't allowed to use the US network,and when they were allowed to,the messages were in very simple text without photos.

    The World Wide Web was invented by a British scientist named Tim Berners-Lee in 1989.He wanted to send documents to other scientists,so he developed the World Wide Web.This allowed him to send and receive scientific documents with text,drawings and photos(also called multimedia documents).In the 1990s,more and more people began to use the Internet and the World Wide Web.

    So what's the difference between the Internet and the World Wide Web?The Internet is the hardware.It allows us to communicate with other people.The World Wide Web is the software.It allows us to create, see and read multimedia documents.

    The Web is made up of millions of documents called Web pages.These pages are held in computers all over the world.Many people have a favorite website with a number of Web pages on the same subject.

    The email is a way of using your computer to send and receive messages.It's cheaper and quicker to use emails than send normal mails.New users call the normal mail “snail mail” because it's too slow.It took 50 years for 100 million people to listen to the radio.It took 15 years for 100 million people to watch television.By the year 2000, it had taken only about three years for 100 million people to use the Internet.What will happen next on the Internet?

    Solar storms shake Earth's magnetic field(磁场). They not only influence human technology, but also animals, reported Forbes.

    Studies show that many animals use changes in Earth's magnetic field to find directions. These changes provide the animals a general compass(指南针) for south and north. Animals can also use them as landmarks.

    For example, scientists have found special cells in part of a bird's eye nervous system(神经系统). They seem to react to changes in the magnetic field.

    Some fish species, like the common trout，have cells with magnetic sensors in their nasal cavity(鼻腔). In 1994 "magnetic sense" was also discovered in sea turtles.

    Some whale species may use magnetic sense to navigate (导航) the oceans. A dysfunction of this sense may explain the still mysterious beachings (动物搁浅). Sometimes several hundred animals, such as whales and dolphins, are driven out of water along beaches. They usually can't breathe under their own weight and die slowly.