Do you like music? Probably. But do you like all kinds of music? Want to say no? Well, before answering this q{#blank#}1{#/blank#}, you'd better have a good understanding of what music is. A music teacher wanted to tell his students the difference b{#blank#}2{#/blank#} music and noise (噪音). He brought many wooden blocks (大 块) of different sizes to class. The students were very s{#blank#}3{#/blank#} to see him throw the blocks at the wall. Everyone thought it was noise. He then took the same blocks and threw them at the wall a{#blank#}4{#/blank#}. This time, however, he threw them in a special order (次序). The students quickly found it was a tune (曲 子). "So," asked the teacher, "what is music?" The answer is that it's organized noise.

    The world is in danger. At one time there were 1,300 different plants, trees and flowers in Holland, but now only 860 remain(剩余). The others have been destroyed(破坏) by man. We are changing the earth, the air, the water and everything that grows and lives. We can't live without these things. If we continue doing like this, we will destroy ourselves.

    What will happen in the future? Perhaps it is more important to ask "What must we do now?" The people who will be living in the world of tomorrow are the young of today. A lot of them know that conservation(对自然环境的保护) is necessary. Many are helping to save our world. They plant trees and protect animals in forest. In a small town in the United States, a large group of volunteers cleaned the banks of their rivers. Young people may hear about conservation through a record called No One's Going to Change Our World. It was made by the Beatles, Cliff Richard and other singers. The money from it will help to protect wild animals.

    Today more and more children wear glasses before going to middle school. They keep their eyes watching TV or playing computer games for a long time. Eyes are the windows of our hearts (心). We use our eyes to see everything around us, so we should know how to protect our eyes.

    Love our eyes. When we open (睁开) our eyes every day, we can see the lovely friends and parents, beautiful flowers and green trees. If our eyes don't work, how can we see the world. In our eyes, everything and everywhere is dark. It's like a house with no light (光). How important our eyes are!

    Relax our eyes. First, stop to relax 30 minutes when using the computer for an hour or two. Next, remember to do eye exercises every day. Then, looking at green trees also helps a lot. In these ways, our eyes will feel relaxed.

    Have good habits. When writing homework and reading, it is important to keep a distance (距离) of 30 cm between your eyes and books. Remember to use our eyes in a right way. Don't read in bed or on a moving bus. Eat something healthy for eyes, such as carrots, fish and eggs.

    Follow my advice (建议) and get good habits. It's time to say goodbye to thick (厚的) glasses.

Nowadays in school life, a lot of students develop a fear of tests. It's not because tests are something to be afraid of. Most students are afraid of tests mainly because they don't always think they are well—prepared and they don't have enough self—confidence. If you follow the advice below, it's not difficult to overcome your fear of tests.

People who know that they are not well—prepared are usually those who fear tests most. However, most students don't know when they are truly prepared for a test. As long as you know that you have studied well and long enough, you have reason to believe that you are well—prepared.

Be confident about yourself. Confidence before a test can bring about two results: either you fail the test and feel as if your confidence was unfounded (毫无根据的) or you could actually do well in the test because of your confidence. Some students find that they experience the first result. However, this is only because those students might not have followed the first advice mentioned above. As long as you have studied well, you will be more confident of your chance to succeed in a test. If you feel as if you have not studied hard enough, then you will not be as confident as you should be.

Ask your teacher in advance (提前) about the material that is going to be covered in the test. In this way, you will know what you should prepare for and you can get confidence in the test. But you have to be brave enough to ask. Most students do not ask unless their teacher gives the information first, so make sure that you ask.

You should know that tests are only telling if you have got the knowledge, not how good or bad your IQ is. So, even if you do badly in one test, you should know that there are other tests to come. As long as you think that there is another tomorrow, you can overcome your fear of a test. However, make sure that you are going to prepare well for the other tests.

Fear can be a problem in the process of achieving success. However, with the right attitude (态度) and preparations, you can overcome your fear of tests by using these suggestions.

    Beauty sleep is a real thing, researches have shown that people who have enough sleep look more attractive (有魅力的) to others.

    A few bad nights are enough to make a person look especially "more ugly", their sleep experiments show.

    The researchers asked 25 university students to join in their sleep experiment. They were asked to get a good night's sleep for two nights.

    A week later, they were asked to sleep for only four hour every night for two nights in a row. The researchers took make—up free (素颜) photos of the volunteers after both the good and the bad sleep.

    Next, they asked 122 strangers to have a look at the photos and judge (评价) them on attractiveness, health, and sleepiness, as well as asking them: "How much would you like to make friends with this person in the picture?"

    The strangers were good at judging whether the person they were looking at was tired, and if he was sleepy, his attractiveness score would be low.

    The strangers also said they wouldn't want to socialize with the tired students. The researchers say this is natural for people. An unhealthy-looking face makes people run away. In other words, people don't want to hang around with people who might be ill.

    Dr Brewer, an expert at the University of Liverpool said: "Judgment of attractiveness is often unconscious (无意识的), but we all do it, and we are able to judge on even something small like whether someone looks tired or unhealthy. This study is a good reminder of how important sleep is to us."

    Grandparents are respected in many human societies. But telling stories about old times and overfeeding grandchildren seem like human qualities. Are these classic grandparent behaviors really limited to humans?

Do any animals know their grandparents the way people do?

For most species on Earth, the answer is certainly " No" . " Usually, there aren't grandparents around anymore when an animal is born,"  said Mirkka Lahdenpera, a biologist at the University of Turku in Finland. " Even if an animal's life span does overlap (重叠) with its grandparents', most species spread out to avoid competing for resources, so the chance of running into a grandparent is slim." 

But there are a few clear exceptions, primarily among mammals (哺乳动物) that live in close social groups. In troops of langur monkeys in India, older females lived together with their daughters and grandchildren. The grandmother langurs defend the group's babies against attacks and even give their own grandchildren special treatment.

Many whale species, too, travel in family groups that include both grandmothers and grandchildren.

Elephant herds are also famously matriarchal. They are led by a grandmother, who can live to around 80 years old, and are generally made up of her daughters and their young. The females in a herd form close bonds and work together to raise their young.

Lahdenper found that the babies of young mothers were eight times more likely to survive if their grandmothers lived near them than if they didn't. When the young mothers were older and more experienced at raising babies, this beneficial grandmother effect disappeared even if the actual grandmothers were still around.

Indeed, most evidence for the benefits of grand parenting comes from mammals. But in 2010, researchers found that in troops of insects called gall-forming aphids, older females defend their relatives after they've stopped reproducing (繁殖).

And what about grandfathers? Studies of humans in recent decades have shown that a living grandfather can improve a person's mental health and other indicators of well-being. But there's no evidence of that in the animal kingdom. Male animals rarely socialize with their own children, let alone any grandchildren.