为了解某校高三学生的视力情况，随机地抽查了该校100名高三学生的视力情况，得到频率分布直方图如下图，由于不慎将部分数据丢失，但知道前4组的频数成等比数列，后6组的频数成等差数列，设最大频率为a，视力在4.6到5.0之间的学生数为b，则a，b的值分别为   (　 　)

    We often see top students around us and everyone knows about them. Let us take Jenny as an example. She is the monitor of our class. She spends a lot of time working for our class. But she always gets good grades in all subjects. How do students like Jenny do that? When I asked her, she said, "Hard work is not the whole story. It's not how long you sit at the desk with your books open. It's what you do as you are sitting." In fact, we can see many top students spend fewer hours on their studies than their classmates. Jenny gave me some valuable suggestions.

    If your math teacher gives you five exercises, you should do six. If your Chinese teacher gives eight pages of reading, you should read nine. The more you practice, the more you learn.

    Studying is a matter of your personal interest, so choose the way you are most comfortable with. Some people like working at night when the house is quiet, while others like doing their work early in the morning. However, others like studying as soon asthey arrive home from school while the work is fresh in their minds. No matter(无论) which way suits you, try to do your best.

    Studying is your business and the business comes before entertainment(娱乐). When you are studying, phone calls should go unanswered, TV shows unwatched, snacks given up. Studying is the only thing in your mind. Nothing can pull your attention away from what you are studying.

    Studying is like eating. You should eat a little at a time. You can plan what to do today, but don't do too much. When you can't finish the work you planned to do, you will feel stressed and may lose confidence. On the other hand, you will not study well without a good plan. It all depends on how you manage your time.

    The students who hand in a clearly written paper are already half way to get an A. Tidy papers are likely to get higher marks than messy(乱糟糟的) ones. When you write clearly and do your work carefully, the thoughts in your mind are clear. You are able to make fewer mistakes.

—I noticed him          in the playground just now.

    “Years ago when I was at the Grand Canyon, I remembered someone coming up to the canyon's edge, taking a shot with a camera and then walking away, like 'got it – done', barely even glancing at the magnificent scene in front of him,” Linda Henkel, a scientist at Fairfield University, US told Live Science.

    Henkel was surprised by how obsessed (痴迷的) people are with taking pictures these days - before dinner, during friends' birthday parties, on museum tours and so on.

    They keep taking pictures because they think that it helps record the moment, but as Henkel's latest study has just found out, this obsession may prevent their brains remembering what actually happened, reported The Guardian.

    In her study, Henkel led a group of college students around a museum and asked them to simply observe 15 objects and photograph 15 others. The next day the students' memory of the tour was tested, and the results showed that they were less accurate in recognizing the objects and they remembered fewer details about them if they photographed them.

    ''When people rely on technology to remember them — counting on the camera to record the event and thus not needing to attend to it fully themselves, it can have a negative impact on how well they remember their experiences,” Henkel explained.

    But there is also an exception: if students zoomed in to photograph part of an object, their memory actually improved, and those who focused the lens (镜头) on a specific area could even recall parts that weren't in the frame.

    So basically, this study is saying that constantly taking pictures can harm your memory. But shouldn't reviewing pictures we have taken help wake up our memories? This is true, but only if we spend enough time doing it.

    “In order to remember, we have to access and interact with the photos, rather than just collect them,” Henkel told The Telegraph. However, previous research has shown that most people never take the time to look over their digital pictures simply because there are too many of them and they aren't usually very organized on their computers.