graph embedding:初初级课文精精听 2010-06-16
新闻背景:
A person can live in the modern world without synthetic substances. But if anyone tries to do it, he will soon miss many common things. Besides plastic pens,combs,and toothbrushes, (1)__________________. Items like briefcases and suitcases are more expensiveif they are made of leather instead of plastic. Today there are many different types of plastics, and the manufacture of them is a very important industry. (2)___________________. They may be hard or soft, and they can be made resistant to fire water and electricity. If a person visits the world's market places, he will find that plastics are being made and used almost everywhere. Plastic articles can be produced at a rather low cost. The machines for moulding them are not large or heavy. (3)__________________. Thus, plastics are both popular and practical, and factories for making them can be found in many countries.