With the ever increasing popularity of online shopping, users' reviews（评价） are becoming more and more important. Since you can't actually touch, smell or hear the product your buying online, these reviews provide buyers valuable information on the product itself. But how reliable（可信的）

Bamaby Bicken took some friends to a restaurant in Manchester that had excellent reviews on a food website. However, she found the service was awful. "We were ignored（被忽略） most of the time. Later

So, how can you get a useful review?Web expert Hilary Saunders has a few top tips. "If there are only a few reviews of a place, it is quite possible that they have been posted by friends or enemies. If there are many reviews, watch out for the reviews that are almost the same in style and are placed at about the same time. even though they are from people with different usernames. The best thing is to look for reviewers who seem to be familiar with the product they are reviewing. 

Although some companies still offer gift voucher（礼券） to anyone who would give their product a five—star review, some are stepping in because they think it's their duty to build an objective（客观的）, and when a customer reports a reviewer that we feel inappropriate（不合适的）, we check and may take it down. "

So next time you see that five star review for something you want to buy, be careful—it could be the work of a false reviewer!

Memory is very important. It helps you remember who you are, where you live, what you have learnt and what you plan to do in the future. 

Some scientists believe that there are three types of memory—immediate, short-term and long-term. 

Immediate memory holds information for less than a second, e.g. the name of a road you have just seen. Then it either forgets it or passes it into short-term memory. Short-term memory can hold about seven items of information at a time, e.g. telephone numbers. It holds them for about 30 seconds. Then it either forgets them or passes them into long-term memory. Long-term memory can hold information for the whole of our lives, e.g. the names of countries or the meanings of words. 

So, how can you improve your memory? 

It is important to exercise your brain. For example, you can do new things and change your daily habits. If you walk a different way to school or take a different bus, you will keep your brain active. You can try to memorize something new. You can try a Maths puzzle（益智游戏）. You can also try to learn new skills or study a foreign language. Your brain gets lots of regular exercise if you do any of these things. 

If you live a healthy life, your memory will work better. You must have a balanced diet（均衡的饮食）. You must give your brain enough time to rest. Unless you get enough sleep every night, you will not remember things well. 

If you want your brain to work well, you also need to relax. If you get too worried, your brain will slow down, and your memory will become less excellent. 

So, to improve your memory, you should exercise your brain, live a healthy life and stay relaxed. 

Every year some birds fly south when days turn cold and leaves from trees start to fall. They travel a very long way to find a warmer winter. This travel is called migration (迁徙). 

Birds do that because in winter most of the plants die and some insects (昆虫)hide. They fly away to find enough food. The next year when there is plenty of food for them to eat, they will come back. 

Birds fly in some ways. For example, they fly in groups like the letter V or in a row. The trip is often hard and it may be dangerous. But they never get lost because they look at the sun, the moon and stars. 

There is an English saying,"Laughter is the best medicine. " Until recently, few people took the saying seriously. Now however, doctors have begun to look into laughter and the effects it has on the human body. They have found that laughter really can improve people's health.

Tests were carried out to studythe effects of laughter on the body. People watched funny films while doctorschecked their heart, blood pressure, breathing and muscles. It was found that laughter has similar effects to physical exercise. It increases blood pressure, makes the heart beat quicker and makes people breathe deeper; it also works several groups of muscles in the face, the stomach, and even the feet. If laughter exercises the body, it must be beneficial. 

Other tests have shown that laughter appears to be able to reduce the effect of pain on the body. In oneexperiment doctors produced pain in groups of students who listened todifferent radio programmes. The group that tolerated (忍耐) the pain for the longest time was the group which listened to a funny programme. The reason why laughter can reduce pain seems to be that it helps to produce a kind of chemical in the brain which diminishes both stress and pain. 

As a result of these discoveries,some doctors in the United States now hold laughter clinics, in which they help to improve their patients' condition by encouraging them to laugh. They have found that even if their patients do not really feel like laughing, making them smile is enough to produce beneficial effects similar to those caused by laughter.

There is a fish called the angelfish （神仙鱼），which can change from female to male. No，it cannot do it by simply wishing to become male. The change happens for a speeifie reason. 

The angelfish live in groups. And each group has one male fish，which is blue in colour，and four female fish，which are yellow in colour. 

The male angelfish is the strongest and largest member of the group. When the male fish dies，the largest female fish in the group begins to change its looks. She begins to grow larger in size. After a week，she starts changing colour，from yellow to blue. Slowly，she begins looking like a male. Two weeks later，black stripes （条纹） appear on her body. She is now really male. 

The angelfish are among the most brightly coloured fish of the sea. People prefer to keep them because of the interesting patterns （图案） on them. People like to keep them because of their good looking. Often，the young ones have different colours from the old ones. At night their colours may change. 

Sharing Mind Maps with Classmates

There are different kinds of mind maps. You can choose from them to complete the tasks clearly.

Every year, millions of birds are killed or hurt when they fly into buildings. Why does this happen?  Birds are flying into windows and tall buildings that are all covered by glass.

Many birds fly from one place to another. Most of the time, they live in the wild, such as forests and wetlands.  They might see small trees and flowers inside a window and want to rest on these plants. The birds do not know there is glass between them and the plants.  

Some birds fly at night. They use the moon and stars to help guide them in the right direction. Tall buildings with lights on at night can confuse（迷惑）the birds.  The birds see the light, but they cannot tell that the light is coming from inside a building. They fly toward the light and crash into a building. On many mornings, there might be several dead birds lying on the ground.

  Many office buildings now turn off their lights at night. This helps reduce the number of birds that fly into buildings and it also helps save energy.

Brainstorming is the practice of coining up with ideas or solutions. But we do have some rules to follow for successful brainstorming.

Focus on quantity （数量）over quality. When it comes to brainstorming, the more ideas, the better.

Don't worry about the quality of your ideas for now. Remember that your goal is to come up with as many ideas as possible. Even if none of them are perfect, you'll still have many creative ideas to use for your final plan.

Encourage big or unusual ideas. Although unusual ideas may not be immediately practical, just creating those ideas gives your brain training. It can also help to produce creative solutions that are hard to come up with.

Don't say no to the ideas of others. You can put together the best parts of different ideas to create new, even better ones. Even if you're not brainstorming as a group, you should still think about sharing your ideas with others and asking them for their advice.

You don't have to regard yourself as a very creative person to come up with excellent ideas and solutions at once. Even if you don't find the perfect solution, just practicing it can help to improve your creativity. Put these tips together and you are sure to come up with some great ideas.

The invention of barcodes (条形码) is based on a very simple idea. We only need to give each product a specific number and print it.  We could simply print the number itself. But this can cause problems. For example, an unclearly printed "seven" could look like a "one" to a computer. It's also true for "three" and "eight".  We need a better way of printing numbers so that they can be read correctly at high speeds. That's the problem barcodes solve.

Each number in a barcode is shown by seven blocks of the same size.  For example, the number "one" is shown in turn by two white stripes (条), two black stripes, two white stripes, and one black stripe. 

A barcode includes different parts and each one provides a specific meaning. The first part of a barcode tells you the country where the product was made. For example, 690—692 is the barcode for China. The final part is about the product itself. This is how barcodes work.