Earthquake are common: thousands of them happen each day. But most are too weak to feel. During a 1 earthquake, there is often a great noise first. Then the earth 2 terribly and many houses fall down. Railway tracks break and trains go 3 lines; a great many factories are destroyed; thousands of deaths are caused, and many more lose homes. Besides the great damage and deaths caused by the earthquake 4, other accidents such as fires often 5.

    More buildings are destroyed and more deaths caused.

    It is well-known of the dangers of an earthquake, 6 for centuries man has been making researches on earthquakes. More than 2000 years ago, 7, a Chinese scientist named Zhang Heng invented a machine which could 8 from which direction the seismic waves（地震波）had come, and this machine is still used by scientists today. Now we know much more about earthquake and    9 they happen, but we still can't  10 exactly when and where an earthquake will happen, and can't stop it from happening.

    The lion is one of the most fierce (凶猛的) animals in the world. Lions can be 1 in Africa and India. Lions in Africa can live without water for about one month. Lions are also popular animals in the 2 . Almost every zoo around the world has a few lions.

    It is very 3 for people to tell male and female lions from each other. You can judge (判断) simply by their appearance. A male lion has mane while female lions do not have. Male lion 4 than female lions. A male lion usually weighs about 200 kilograms which is always heavier than a female lion. Both male and female lions have very 5 mouths. They can break the backs of other animals 6. Lions feed on other animals and one lion usually kills between ten and twenty large animals each year for 7 .

    It's unusual for lions to kill people. However, in 1898 two lions 8 and ate over one hundred people in Kenya before they were shot by a British man named P.J. Patterson. This 9 became the subject (主题) of a 1996 Hollywood movie called The Ghost and the Darkness. Now the Indian lions are endangered. It's really necessary for us to 10 the animals, or we won't see them again. Animals are our friends. It is our obligation to protect them.

    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

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    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.