Smog is a big problem in many Chinese cities. But it seems that besides wearing a mask, few of us know what has caused the smog and what to do to beat it. In fact, burning too much coal and oil are the main causes of PM2.5 and smog (雾霾).

    To solve the problem, we should clean our coal and oil or replace them with cleaner energy such as natural gas. We ordinary people can do something to help control smog, too.

    What can we do to help beat the smog?

    Choose to take public transportation. Though many people have their own cars, they had better take public transportation, such as the subway or buses. If the destination (目的地) is not far away, you can also walk ________ ride a bike.

    Call the hotline 12369. You can call the number for complaints and questions about environmental issues. It is run by China's Ministry of Environmental Protection. If you call the number, some officers can come and try to solve the issues, so please remember it.

Report and resist pollutant source. If you find any pollutant source, take a picture of it and post it on your social media accounts. Remember to add “@local environmental departments” on weibo. Payattention to factories that pollute the environment and don't buy products from them.

    Our environment will become better if everyone is concerned (关注) with the environment. This is what we need in the future. So everyone can do something to beat smog.

    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.

    Light and shadow（影子）are friends. They usually go together. We receive light every day. At the same time, we produce shadow.

    Light cannot shine through you. Your body stops it from passing. There is a dark spot on the ground next to you. The light cannot reach the dark spot. This is your shadow.

    At noon the Sun shines over your head. Your body stops very little light from reaching the ground.

    We love light, especially sunlight. Without sunlight, life on the Earth is impossible. Most of us like to stand in the shadow of a tree in summer. But some people are afraid of their own shadow at night. They do not want to walk in a dark street. They do not want to see the shadow either. But still light and shadow usually go together.

    What was discovered by accident? The answer is penicillin (青霉素). It kills germs. By killing germs, it saves lives. Suppose you are sick. You go to a doctor. She examines you. She says you have a “staph” infection (葡萄球菌感染). She gives you some medicine. You take it. The medicine knocks out the staph. Soon you are well. Before penicillin, this would not happen. Staph was almost sure death.

    Everyone wanted a medicine. Laboratories worked day and night. They grew the staph in small dishes. Then they tried to kill it. Nothing worked.

    The laboratory dishes had covers on them. They kept things from falling into dishes. Molds (霉菌) were a big worry. They are always in the air. You can't see them. They're too small. There are thousands of different molds. Molds can make an experiment (实验) fail. That's why dishes are covered.

    Dr. Alexander Fleming was working to kill the staph germ. He worked for years. One day he took a cover off a dish. He looked inside. There was a thick growth of staph germ. There was also some mold. Then he saw something strange. Where the mold was, there was no growth of staph. This is what Fleming probably thought. “By accident, I found a mold to kill the dreaded staph.”

    This is how penicillin was found. But here's the real miracle (奇迹). There are thousands of kinds of molds. But only one kind can kill staph. The mold must have fallen into the dish a few days before. The cover was probably off only a few seconds (秒). In those few seconds the right mold fell into the right dish. Another man might have thrown the dish away. But Fleming was very careful and smart. He understood what the mold did. How lucky the humans were!

    Man has a big brain（大脑）. He can think, learn and speak. Scientist once thought that men are different from animals because they could think and learn. They know now that dogs, rats, birds can learn too. They are beginning to understand that men are different from animals because they can speak.

    Animals cannot speak. They make noises when they are afraid, or angry or happy. Apes（类人猿）can understand some things more quickly than men. One or two of them have learnt a few words. But they cannot put words together to make sentences. They cannot think as we do because they have no languages. The language is a wonderful thing. Man is able to build a modern world because he has language.

    Each child can speak his own language very well when he is four or five, but no animal learns to speak. How do children learn it? Scientists don't know. They only know that man can speak because he has the brain.

    Pisces is the twelfth star sign. There is a legend about its name.

    Long, long ago, there was a war between gods and a bad monster (怪物). It lasted ten years. One day, the gods were surprised to find that the monster was coming towards them. The goat god Pan shouted a warning and tried to change himself into a fish. One god, Aphrodite, took her little boy Eros and tried to hide among the bushes near Euphrates River. She was the god of love and her son was the god of war. It is said that two fish swam to carry Aphrodite and her child to safety. Some people also believe that Aphrodite and Eros changed into fish themselves and swam away to safety. Later the fish represent Aphrodite and her son Eros.

    As they appeared in the sky, the two fish were tied together by a rope (绳子). Some said that Aphrodite tied the little boy to her body so that he would not get lost as they swam away to safety. That's the story about Pisces.

    In Western countries, some people believe people will share similar characteristics if they have the same star sign. So if you're born between February 19th and March 20th, your star sign is Pisces. It means that you are generous, easy-going and creative.