We each have a memory. That's why we can still remember things after a long time. Some people have very good memories and they can easily learn many things by heart, but some people can only remember things when they say or do them again and again. Many of the great men of the world have got surprising memories.

    A good memory is a great help in learning languages. Everybody learns his mother language when he is a small child. He hears the sounds, remembers them and then he learns to speak. Some children are living with their parents in foreign countries. They can learn two languages as easily as one because they hear, remember and speak two languages every day. In school it is not so easy to learn a foreign language because the pupils have so little time for it, and they are busy with other subjects, too.

    But your memory will become better and better when you do more and more exercises

    Global warming means the temperature of the Earth is getting higher and higher. If the Earth gets 1, some of the following things could happen:

    The sea level could 2 because of the melting of sea ice.

    Many animals that live on the ice might 3 out.

    There could be more floods(洪水), 4 near the sea and rivers.

    Some plants and animals might die because they cannot live in high 5.

    Global warming is a very 6 problem now. There is something we can do to help to slow it down.

    Scientists have been studying global warming for years. They have found that some things that people do in everyday life make much gas that 7 global warming. One big cause of this is the burning of oil, gas and coal for energy for our cars and homes. This gives off too much greenhouse gas. We can do something to cut 8 on the amount of greenhouse gas.

    ⒈ We can really help by using less energy in life, and less gas in our family cars. We should turn off the 9 and turn down other electrical equipment. We should walk more and use cars less.

    ⒉ 10 can take in some of the greenhouse gas. So we should plant more trees.

Orchids and the environment

    The orchid is a beautiful flower that can grow indoors or outdoors. There are over 25,000 different species of orchids, so it's one of the largest families of p{#blank#}1{#/blank#} in the world. Orchids can come in many different c{#blank#}2{#/blank#}as well, such as white, purple, pink, blue and yellow. There are several conditions that help orchids grow so well. Orchids need the right temperature, as well as the right amount of sunlight, soil, and water in order to l{#blank#}3{#/blank#}.

    F{#blank#}4{#/blank#} indoor orchids, it is much easier to control these conditions. For example, orchids usually need to be watered once a week, and you can control how much water you give to the plant. Also, many orchids grow best if they had indirect sunlight b{#blank#}5{#/blank#} direct sunlight will burn them. Indoor orchids can be placed near windows with curtains or blinds. This will protect them and give them the indirect sunlight they need.

    However, as to orchids that grow outdoors in the wild, global warming can become a threat. Unfortunately, global warming affects temperature, light and rain. All these factors will affect the way orchids live and grow. Most orchids will live c{#blank#}6{#/blank#} within a narrow temperature range of 18.3 to 23.8 degrees Celsius. Global warming can increase temperatures beyond the natural range for these flowers. Unfortunately, this can destroy orchids because they can't survive in hot, dry conditions. Second, air pollution can create acid rain. Acid rain is created when gases from fossil fuels combine with water in the air to form acids. When acid rain falls on plants and trees, it destroys the n{#blank#}7{#/blank#} balance of the soil and kills them.

    Suppose you find a bright yellow bike on a street corner in the city. You hop on(跨上)it and 1. But wait—isn't this stealing? No, it isn't. 2 shouts, "Stop! Thief!" That is 3 this free ride is just fine with the city.

    You 4 find hundreds of free yellow bikes in some US cities. The idea began in Portland, Oregon, in 1994. People saw a need for 5 transportation, and they wanted to help 6 pollution. So, to get citizens(市民) 7 their cars and onto pollution-free bikes, they 8 the Yellow Bike Project.

    The 9 bikes are painted bright yellow and placed throughout the city. People can hop on the yellow bike and ride to run errands(短程差事), to work 10 to school. Then, they leave the bike for the 11 rider. There have been times when bikes have been stolen, but most people 12 the rules, because they think it is not wise to 13 the bike that's already free.

    Portland's 14 was quickly loved by a lot of people. Within two years of its starts, similar programs were 15in cities in six other states.

    In real life, robots are mainly used in factories. They do many different jobs. Usually these jobs are too 1, difficult or boring for humans.

Robots also help disabled people and people who cannot look after 2. For example, scientists are making a robot to help 3 people. Now many of them have a dog to help them. The dog is called a guide dog. In the future, guide dogs might be robot dogs.

One robot dog is called Meldog. It has wheels. It usually "walks" 4 its owner. It is very clever. It knows the speed of its owner's walk. Meldog talks to its owner by 5. The owner wears a special belt. This belt 6 instructions to the owner from Meldog such as "Stop here", "Turn left" and "Turn right".

    In the United States, another 7 of robot helps disabled workers. This robot, called Kilroy, helps disabled computer operators. The robot 8 the sound of its owner's voice. It follows instructions such as "Turn the page" and "Make a cup of coffee".

    Robots are also used in American 9. They can do simple jobs. For example, they shave (刮脸) patients and brush their teeth and take meals from the kitchen to patients' rooms. It never gets lost 10 this robot has a map of the hospital in its computer memory.