Soon computers and other machines will be able to remember you by looking at your eyes! The program works because everyone's eyes are different. So in the future you won't have to remember the number of your credit card when you want to use a machine or take money out of a bank. You'll just have to look at the machine and it will be able to tell who you are.

    The eye-recognition（眼睛识别）program has already been tested in shops and banks in the USA, Britain, Spain, Italy and Turkey. Soon this technology will take the place of all other ways of finding out who people are.

    Eye-recognition is a course of recognizing iris（虹膜）, which includes the following steps. First, a kind of machine needs to collect different examples of one's iris from his eyes and store them. Second, when this person goes to the bank to take out money, this machine will have iris feature extraction（采集）. Then, this machine will compare the examples kept in it with iris feature extraction. Once the examples and the feature extraction are the same, this person will be identified, and he will take out the money from the bank successfully.

    However, scientists are also working on other systems. Machines will soon be able to know you from the shape of your face or hand or even your smell! We already have machines that can tell who you are from your voice or the mark made by your finger.

    Eye-recognition is better than other kinds because your eyes don't change as you get older, and don't get dirty like hands or fingers, and even twins have different eyes. So the eye-recognition program can be up to 94% correct, depending on how good the technology is. However, some other programs may only be 51% correct now. In Britain, it was found that 91% of people who had tried it said that they liked the idea of eye-recognition.

    In the future your computer will be looking you in the eye. So smile!

    Height is just one of the features your genes(基因) decide. In fact, because you have two parents, your genes provide you a height that usually lands somewhere between the height of each parent. If both your parents are tall, then most probably you will be tall, too. But if you have questions about how tall you're going to be, ask your doctor if he or she can help you find them out.

    But genes don't decide everything. For example, eating an unhealthy diet can keep you from growing to your full potential(潜力). Getting plenty of sleep and enough exercise will help you grow to the expected height.

    It's natural that you're wondering how fast you should grow. There's no perfect or right answer. Generally speaking, kids grow about 6 cm a year between age 3 and the time when they start puberty.

    Your doctor will know how your growth has been going over the years. 2 cm here and 3 cm there make a little difference to the height you're at now. How have you been growing up to this height? What other changes may your body be going through?

    Don't be amazed if you seem to have grown a lot in a very short time. Everyone has a growth spurt(高峰) during puberty. The age for starting puberty is about 10 for girls and about 11 for boys. But it can be earlier or later — between 7 and 13 for girls and 9 and 15 for boys.

    You'll usually begin to notice that you're growing faster about a year after your body starts to show the first changes of puberty.

根据材料内容选择最佳答案。

    April 22 is Earth Day. Everyone on Earth should care about and protect the earth!

    The earth has warmed by about 1°F (华氏度) over the past 100 years, but why and how? Well, scientists are not quite sure. Maybe the earth gets warmer and warmer on its own. But many scientists say that people are doing many things which makes the earth warmer. First, greenhouse effect (温室效应) is a very important reason for the change of the earth. People give out too much energy into the air every year. It makes the earth warmer. Climate (气候) change is another important reason. Sometimes it becomes too hot and sometimes too cold. Sometimes there is too much rain and sometimes too little. The change of the climate makes the earth warmer. In turn, the warmth of the earth changes the climate, too.

    When the earth becomes warmer, there may be more rain and a rise in sea level. It will affect the growth of plants, animals and people. On a Pacific island, 100 people have to move to higher ground because the sea is rising. These people can no longer live on the coast. Before that, two islands without people went underwater in 1999. Scientists say that the seas can rise by nearly one meter by 2100.

    People can affect the earth's air, land and water. As for us, we can do many things to protect the earth. For example, we can use fridges less. We can tell more people about protecting the earth.

Dear sir,

    I am doing a project(课题) at school about animals in danger. I think the situation all over the world is really terrible.

    Firstly, I feel so sorry for the giant panda. Pandas mainly live on bamboo. A panda can eat about half its body's weight(重量) of bamboo in 24 hours！That's a lot of bamboo. I think we should try to do more to stop cutting down their forests. We would be so sad if they disappear.

    Secondly, what we should try to protect more is the Chinese alligators(短吻鳄) . They live in some parts of eastern China. They live in freshwater rivers and lakes but the water in some places isn't clean enough for them to live in. It's really dirty in fact. The government should stop factories from polluting the lakes and rivers.

    If we protect these beautiful animals in China, more people may come to China to visit our beautiful country, especially to see the quieter areas in the country. Now most visitors just see the cities.

    I hope you will encourage(鼓励) more people to think about such an important subject.

Yours,

Huang Jing