The US public uses about 50 billion water bottles a year and most of those {#blank#}1{#/blank#} bottles are not recycled, according to Elizabeth Royte's book Bottlemanid: How Water Went on Sale and Why We Bought It.

More than $100 billion is spent every year on bottled water in the U.S. in many developing countries where there isn't a safe {#blank#}2{#/blank#} of tap water, bottled water is the only choice.

In the US, tap water is controlled by the government and often {#blank#}3{#/blank#} for dangerous substances(物质). Each American drinks 79 litres of bottled water per year {#blank#}4{#/blank#}. The bottled water industry is so successful that it has outpaced milk, coffee, and juice in the number of gallons of drinks sold – putting it behind only beer and soda.

    A thousand years ago, Hong Kong was covered by a  1 forest. As more and more people came to live in Hong Kong, these trees were 2 and burnt. Now there are only a few forests left and we call these 3, a small area covered with trees.

    Elephants, tigers and many 4 animals were living in the thick forest. Early farmers needed fire to keep themselves 5 in winter, to cook their food and to keep away the dangerous animals. They 6 rice and kept pigs and chickens in the valleys. They cut down the trees and burnt them. Elephants quickly disappeared 7 there was not enough food for them. So did most of the wolves and tigers. Monkeys and many other animals soon 8 in the same way.

    There are about 36 different animals living in Hong Kong now. One of the most interesting of Hong Kong's 9 is the barking deer. In Hong Kong the barking deer has only a real enemy human beings. There are now not 10 barking deer left. So it is important for people to protect wild animals.

    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 a number 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(取代)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 of 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 of 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(科技)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 at you in the eye. So smile!