题目内容

Metals are melted by workers ________ they can be made into different shapes.

A.
because
B.
so that
C.
since
D.
then

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Metals are melted by workers ________ they can be made into different shapes.

[　　]

A．because	B．so that
C．since	D．then

根据汉语提示写单词

Metals are ________(熔化)so that they can be made into different shapes．

根据短文内容在空白处填写一个适当的单词。

　　Fire can be very useful, but it can also be very (1) _____. Be careful when you start a fire.

　　Millions of years ago, early men used a stick, a large (2) ____ of wood and dry leaves to make a fire. Early men found fire very (3) ____. At first, they ate raw meat. Then they discovered fire and started eating (4) ____ food. At night, they used fire to (5) _____their families from wild animals. They also used fire to give them light and keep them warm in winter.

　　Nowadays, people do not only use fire to (6) _____ food or boil water. In factories, workers use it to melt metals. Metals are melted so that they can be made (7) ____ different shapes.

　　Factory workers also use fire to make glass. Have you ever seen workers blowing glass? They make bottles and vases of different sizes and shapes by (8) ____ glass. First, the workers put some hot glass onto one end of a long metal pipe. Then they start blowing from the other end of the pipe.

　　In some places of the world, people use fire to (9) _____ rubbish. Every day, they collect and burn a huge amount of rubbish. Fire can (10) ____ everything. We have to be careful when we use fire. People may lose their lives and homes or they may be seriously injured in a fire.

　　Every year, hill fires burn a lot of trees. This is because there are many (11) ____and thoughtless people. Careless people forget to put out their barbecue fires. (12) ____ people drop burning cigarette ends everywhere.

Think of all the things you throw away：juice bottles，soda cans，candy covers．It adds up．How much rubbish do you produce? Americans throw away about 1 ton of rubbish per person every year．That's 2000 pounds of rubbish! Most of the rubbish gets covered in big holes in the round called landfills(垃圾掩埋法)．

A lot of this rubbish can be recycled，or turned back to something useful．The main things we recycle today are made of metal and paper．

People recycle for many reasons．One of the main reasons is to protect resources(资源)．Making new cans out of old ones means less aluminum(铝) is needed for new cans．

This leads to a second reason people recycle：it saves energy．Recycling old aluminum cans take much less energy than making new aluminum．To make new aluminum，you need to mine metal ore(矿石) from the ground，remove it，and refine it，into a finished metal．

Recycling also protects valuable land．By recycling，we produce less rubbish．That means fewer landfills are needed for dropping our rubbish．Because metals are some what costly to make，they are the world's most recycled materials．About two-thirds of all steel(钢) is recycled．

Almost all drink cans are made of aluminum．Americans recycle about one-third of their used aluminum cans．Empty cans are sent to special factories．There，they are cleaned，melted，and made into new pieces of aluminum．

Americans use lots of paper — mostly in the form of newspapers，magazines，and cardboard boxes．In fact，paper takes up more space in landfills than any other material．

Old paper can be cut and made are into new paper．Americans recycle a little more than one-third of their paper rubbish．New papers are made from trees，each ton of recycled paper saves about 17 trees!

76. You can most probably read the passage in _______．

A．a science book B．a Chinese book C．a history book D．a geography book

77. Which material isn’t mentioned in the passage?

A. Paper B. Metal C. Wood D. Water

78. Why do people recycle rubbish?

A．To protect resources because it's hard to make new resources．

B．It can save energy，because the resources are limited(有限)．

C．To protect valuable land，because there is no place to bury rubbish．

D．To protect resources，save energy and protect valuable land．

79. Which of the following is RIGHT?

A．People recycle paper from the trees． B．Papers take up less space in the landfills．

C．Americans recycle a little more than 1/3 of their paper rubbish．

D．To recycle paper can't protect the environment．

80. The main idea of the passage is _______．

A．To let us know it is a big job to deal with rubbish． B.To explain the reasons for rubbish recycle．

C．To describe how to recycle metal and paper．

D. To explain how to recycle rubbish and why to do so．

Metals are melted by workers ________ they can be made into different shapes.

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