People use money {#blank#}1{#/blank#}  food, books, bicycles and hundreds of other things they {#blank#}2{#/blank#} .When they {#blank#}3{#/blank#} ,they usually get paid in money.
    Most of the money used today{#blank#}4{#/blank#}  metal or paper. But in ancient times people often used all kinds of things as money. One of the first kinds of money was shells（贝壳）.
    In ancient China, cloth and knives {#blank#}5{#/blank#}  money. Elephant tusks（象牙）,monkey tails（尾巴）and salt were used in some parts of Africa. Rice was also a kind of money used by the ancient people on some islands. Cows and other animals were used as money. too.
The first copper（铜）coins {#blank#}6{#/blank#}  China. They were round and had a square（正方的）hole in the center. Different countries have used different metals for their money. Later some countries {#blank#}7{#/blank#}  to make coins of gold and silver（银）.But gold, silver and copper were heavy {#blank#}8{#/blank#}  when people needed a lot of coins to buy something expensive. The Chinese were the first {#blank#}9{#/blank#}  paper money. The first paper money didn't {#blank#}10{#/blank#}  like the paper money we use today.

    Exercise comes from a Latin word that means" to keep busy". Keeping busy is a way of keeping healthy. You need exercise {#blank#}1{#/blank#} your mind, your body, and your social skills（交际能力）.

    Exercising your mind

    Exercise {#blank#}2{#/blank#} improve your mind. Everyone should do some mental（智力的）exercises every day. These {#blank#}3{#/blank#} of exercises help you think clearly. They help you solve problems quickly and {#blank#}4{#/blank#}. They kelp you study and learn new things to make life more {#blank#}5{#/blank#}.

    You can do mental exercises by yourself {#blank#}6{#/blank#} with other people. You can read and think by yourself. You can also play a thinking game with your family.

    Exercising your body

    Exercise helps keep your body healthy. A healthy body helps you sleep well and work well. Physical exercise {#blank#}7{#/blank#} you look and feel fit and healthy.

    Some kinds of physical exercise {#blank#}8{#/blank#} your whole body. These include walking, running, jumping rope and swimming. Playing sports is still another way to keep your body in good shape. It exercises {#blank#}9{#/blank#} mind, too.

    Exercising your social skills

    Exercise helps you improve your social skills. Social exercises help you learn to make friends.

    Working and playing with {#blank#}10{#/blank#} are two ways to improve your social skills. They help you learn cooperation（合作）. The more you work at improving your skills, the more successful you'll be.