unit 10 Frightening nature
the great majority of all earthquakes occur in two specific geographic areas. one such area surrounds the pacific ocean and its contiguous land masses. the other extends from the east india to the atlas mountains, including the himalayas, iran, turkey, and the alpine regions. it is in these two great belts or zones that ninety percent of all earthquakes take place. the text refers to two of the strongest quakes in san francisco. as to our country. a large number of earthquakes happened in north china and northwest china. the powerful earthquake of tangshan hap- pened in the city of tangshan, hebei province on july 28th，1976，which caused more than 240 000 deaths and the whole city was destroyed.
nowadays scientists know a little about earthquakes and they still cannot stop these disasters from happening. however，they can warn people who live in these areas by prediction, in advance to take precautions against such disasters. a worldwide earthquake warning network is already in operation at present and is expected to make earthquake prediction several years ahead of time.
4.5r policy
it’s important to learn about protecting our environment. here is a 5r policy for us to consider:
1.reduce:
if you want to reduce waste, you should use things wisely. millions of trees are being cut down to make paper. if everyone uses a little paper carelessly and throws it away, before long we would not have any trees left. other things are also being wasted, and people don’t really know what to do with the large quantities of rubbish produced in large cities, therefore, t is necessary to reduce the amount of waste by every possible means.
2.reuse:
you should always think of reusing the usable things before getting rid of them. give your clothes you do not use or the ones which are too small to the poor. within a family, you may pass on such clothes to younger brothers or sisters. if you wish, you can use buttons and something else to make dolls or toys for your baby brother or sister.
3.recycle:
bottles, cans and paper can easily be recycled. by doing so we save lots of time and money. for example, coke coca cola cans are sent to a factory, where they are smashed flat and melted and metal sheets are made for new coke cans.
4.recover:
when you buy a box of apples, there might be a few which are highly rotten. you have two choices: one is to throw the whole apples away, or you could cut off the rotten parts and use the good parts. in this way, you are recovering the eatable parts of food.