This is a home of the future, a "smart home", where technology can do almost everything. Imagine we are in the year 2050, ①the computer wakes Tom up in themorning as usual. In front of him is a to-do list of the important events for the day, and it is provided by the computer too. According to Tom's request, the computer serves a list of possible dishes. All the dishes are nice.

    As Tom eats breakfast, the computer reminds him to reply to Lucy. Before Tom finishes his next bite, Lucy's computer receives the message. Then Tom goes to the supermarket. The store's system checks his car when he drives to the pickup area and greets him by name. "Good morning, Tom! Your order is in Case4. Thank you for shopping.'' When Tom removes his order from Case 4, all trades are completed automatically(自动地)over the information superhighway. That is, the money is electronically paid into the bank. Soon after arriving at the office, Tom reads another message from Lucy, telling him that she will go to dinner with him.

    The smart home can also do many other things:

    ◆Find things like keys and mobile phones.

    ◆②        (打开或关闭)machines and lights with your voice.

    ◆Clean your home from clothes to buildings automatically.

    ◆Record everything and everyone entering and leaving the house.

    ◆Take care of each member of the family, young or old.

    ③With the development of technology, the smart home will come true in the future. It is sure to play an important part in our life.

    These days, many students like playing 3D games. Do you know what 3D games are like? In most 3D games, game players need to control (控制) a character. The character can be a robot or a soldier (士兵). Game players usually use the mouse to make the character move around in his own world. Game players can find things such as food and weapons (武器) to help them go on with the game. The character can go straight, sit down, turn left, turn right or pick up things in the game.

    Some 3D games have many levels (等级). The character needs to finish different goals for each level. Game players can play against their computers, and sometimes they can play with other players on-line. It's great fun to play 3D games. But playing 3D games for long is not good for our study.

    Only humans speak using words. But all kinds in the animal world can communicate in one way or another. Maybe you have heard about the way bees dance around to send messages to each other and the way dogs bark in different ways to give warnings, to be friendly or to be playful. But did you know about infrasonic communication used by elephants? This is how it works:

    Humans hear low sounds like thunder rumbling in the sky. But we don't hear sounds lower than this. However, animals such as elephants and hippos can hear much lower sounds than humans can. And what's more, they can make those low sounds as well, and they use them to communicate with each other. This is known as infrasound.

    The amazing thing about infrasound is that it travels over several kilometers. Higher-level sounds like the one people can hear, don't travel well through walls, leaves, trees and so on, which is why we can't hear sounds from more than 100 meters away. But infrasound is much stronger and things like grass and trees have no influence on it. Therefore, it can travel much further. Elephants can hear infrasonic calls from four kilometers away!

    There have been reports of people watching groups of elephants feeding or resting and then the elephants suddenly all stopped what they were doing for no reason at all. They obviously heard a warning call from a long way away, but the people didn't hear a sound. In places like a zoo or wildlife park where you can get nearer to animals, it is a bit easier to sense when infrasonic sounds are made. When you stand near mother elephants with their babies in a zoo, you may notice a slight rumbling in the air every few minutes—not loud or strong, but clearly noticed. This is infrasonic communication—the mother elephants “talking” to their babies.

    When the Audet family turns on the lights at Blue Farm, they are using electricity that comes from cows- cow manure(粪肥).

    Cows produce a lot of waste. One cow can create 30 gallons of waste each day. Now imagine the output of over 1,000 cows at Blue Farm. That's really a big amount.

    When farmers clean their barns, they put the waste together，and spread some of it on their fields for fertilizer(肥料). But now places like Blue Farm have a new way of using cow waste. They use it to produce electricity.

    Here's how it works: A big machine moves back and forth cleaning the barn floor. "The cows are animals of habit; they get used to it,and just lift one foot and then another to let it go by. "says Marie Audet.

    The machine pushes the manure into a big 600-gallon tank like a small swimming pool. The tank is called a digester(化粪池) because what happens there is just like what happens inside a cow: Bacteria(细菌) get to work and continue to digest the manure.

    Methane gas(甲烷;沼气) in the atmosphere is known as a "greenhouse" gas because it keeps heat just like a greenhouse does, causing our planet to warm up. That's an environmental concern. But the digester has a good result. Its gas is kept and used to power electric generators(发电机).

    At Blue Farm, the generators make enough electricity to power 400 homes. The Audet family sells the extra electricity they can't use themselves.