根据短文内容回答下列问题

The Moments （朋友圈）section of WeChat has become

    a popular part of the  social networking platform（平台）.

    We can share everything about your life on it with your friends.Some students had a discussion on whether to allow our parents to see our moments.

    We always look forward to World Book Day—it's a chance to share our love of books and reading with even more people! Here are some of the activities in different countries and places to celebrate the World Book Day, April 23rd every year.

    School Children's Books

    School Children's Books are happy that best-selling writer Holly Webb is their World Book Day writer for 2012. Holly has written a large number of books for children and she has written a special Magic Molly story just for this year's World Book Day!

    Reading Package

    On the World Book Day, every primary school student in Britain will receive a package from their school. Inside, there is a story book, a beautiful card and a reading list. Besides these three things, they will also receive a special note, which is worth one pound. Children can use it to buy their favorite books. And they can also enjoy a special price-20% cheaper.

    Share of Reading

    It is an interesting on-line activity which is for one week. People can share their opinions of a book on line. There are also many reading-aloud activities in libraries. For example, in 2010's World book Day the former US first lady Michelle Obama read aloud a book called The Cat in The Hat for more than 200 children in a library.

    Information Card

    It is not easy for people to sail (航海) around the world in quite small boats. Sometimes the weather gets bad. Accidents(事故) can happen easily and quickly.

    One family once had an accident. A big fish swam under their boat and bit holes(洞) in it. Sea­ water came in and the boat soon went down. Luckily these people had another small boat—a lifeboat, so they all got into the lifeboat. They lived in the boat for many days. They ate and slept, and always hoped. At last people in a ship saved them.

    How do people live in a very small lifeboat for a long time? They must be strong in every way. They must have a hope, and they must have a strong desire(愿望)to live. People cannot drink seawater. If they drink a lot of seawater, they will quickly die. They must catch rainwater and drink it. They must also catch fish and birds for food. Lifeboats do not often carry cookers. So people cannot cook their food in the lifeboats. Raw (生的) fish and birds are not very nice but they are their only food. They must eat raw food, or they will die.

    When it comes to the letter grade on your test or homework, you might notice that there is no letter E. Have you ever thought about why that is so?

    In the A, B, C, D and F grading system, the first four letters are typically considered passing grades. An F in this system simply stands for "fail". The word "fail" happens to start with the letter F, which seems to leave out the letter E.

    The first college in the US to use a letter grading system like the ones we use today is Mount Holyoke College. In 1897, they began to use the following grading scale;

    A: 95-100% (excellent)         B: 85-94% (good)      C: 76-84% (fair)

    D: 75%( nearly passed)         E: below 75% (failed)

    We can see the inclusion of E instead of F.

    Gradually, the letter grading system became more popular all over the US. However, many schools decided to drop the E grade and go straight to F. There is no evidence(证据) to really support this, but one possible explanation is that teachers were worried that some students and parents might mistake E for "excellent".

    Why do we have letter grades? Well, part of the reason is that they made grading simpler during a time of great change for schools. As the 20th century began, growing cities and an increase in immigration led to larger school classrooms. Most teachers at that time thought this new letter grading system was an easy, fair and clear way to grade students.

    Today, more and more people think that letter grades don't fully show students' learning. However, as teachers try to improve grading methods, many parents continue to prefer the letter grades they got as kids, as they are familiar and easy for parents to understand. So while they might not be perfect, the letter grades probably aren't going away any time soon.

Differentweather makes people feel different. It influences health, intelligence andfeelings.

InAugust, it is very hot and wet in the northern part of the United States.People there have heart trouble and other kinds of health problems during thismonth. In the Northeast and the Middle West, it is very hot at some times andvery cold at other times. People in these states have more heart trouble afterthe weather changes in February or March.

Theweather can also influence intelligence. For example, in a scientific report,IQ of a group of students was very high when a very strong wind came, but afterthe wind, their IQ was 10% below. The wind can help people have moreintelligence. Very hot weather, on the other hand, can make it lower. Studentsin many schools of the United States often get worse on exams in the hot monthsof the year（July and August）.

Weatheralso has a strong influence on people's feelings. Winter may be a bad time forthin people. They usually feel cold during these months. They might feelunhappy during cold weather. But fat people may have a hard time in hot summer.

Low air pressure may make people forgetful. Research shows that people leave more bags on buses and in shops on low-pressure days. However, at about 18℃, people become healthier and stronger. People feel best at this temperature.

Areyou feeling tired, forgetful or unhappy today? It may be the weather's problem.