Step by Step 3000 第2册 Unit8:Everybody can help the environment(3)

 　　Part 3. PBS——a biodegradable plastic product.

　　Keywords. plastic, new solution, biodegradable plastic, break down, PBS.

　　Vocabulary. PBS, biodegradable, tableware, microorganism, enzyme¹, degrade, dump.

　　Environmental protection is a big issue nowadays. What can be done to help protect the environment?

　　Listen to a news report about PBS—— a biodegradable plastic product, and complete the outline with keywords and phrases.

　　When you go to the supermarket, can you resist using plastic bags? For lot of us, probably won't.

　　Or if you eat out, can you guarantee not to use any plastic tableware?

　　And how about if someone ask you, can you recommend a replacement² for plastic products?

　　Don't say paper. Here is a new solution, biodegradable plastic.b

　　As everyone knows, plastic is a big environmental headache, although it brings us much convenience, like plastic bags, plastic food containers and plastic tableware.

　　But it is perhaps the most harmful of all our garbage. Because it does not easily break down in nature.

　　A researcher from the Chinese Academy of Sciences, Ji Junhui, says he and his colleagues have found a better solution.

　　"When the PBS in the biodegradable plastic comes in contact with microorganisms or enzymes³, the plastic structure will degrade into smaller pieces.

　　And finally, it turns into water and carbon dioxide. This is how the break-down process works."

　　PBS is a chemical component⁴ that is the key to this new biodegradable plastic.

　　It can help the plastic degrade into non-polluting elements.

　　So the broken-down plastic fragments can be absorbed by soil and water.

　　PBS is not an entirely⁵ new product. However, this China-made biodegradable plastic is safer and more heat-resistant.

　　According to Ji Junhui, testing has shown that 90% of this new biodegradable plastic can be degraded within 90 days.

　　And it even takes a shorter period of time if it's buried in a dump rather than exposed to the air.

　　Usually, biodegradable plastic food containers made in other countries will melt when the temperature reaches 60 degrees celsius⁶.

　　While the Chinese product can retain its shape in up to 100 degrees.

　　However, Ji Junhui says high-tech⁷ products often come at a higher price.

　　"PBS product is a bit more expensive than ordinary plastic.

　　Taking a plastic bowl as an example, the PBS bowl can be 20% more expensive than the current plastic bowl we use."

　　Some hotels and restaurants in Shanghai have already started using the new PBS biodegradable plastic food containers.

　　And the product will be popularized in Beijing as well as in other big cities.

　　It will play a role in the 2008 Olympic Games.

　　Besides in the production of plastic food containers and tableware for the Games,

　　PBS biodegradable plastic will also be used to make road signs, team cheering equipment like horns and mini flags, as well as trash bags, umbrellas and eye glass frames.

　　Probably in the near future, we will really be able to say "farewell" to plastic pollution.

1 enzyme   

n.酵素，酶

参考例句：

• Above a certain temperature,the enzyme molecule will become unfolded.超过一定温度，酶分子将会展开。
• An enzyme that dissolves the fibrin of blood clots.能溶解血凝块中的纤维的酶。

2 replacement   

n.取代，替换，交换；替代品，代用品

参考例句：

• We are hard put to find a replacement for our assistant.我们很难找到一个人来代替我们的助手。
• They put all the students through the replacement examination.他们让所有的学生参加分班考试。

3 enzymes   

n. 酶，酵素

参考例句：

• It was said that washing powders containing enzymes remove stains more efficiently. 据说加酶洗衣粉除污更有效。
• Among the enzymes which are particularly effective are pepsin, papain. 在酶当中特别有效的是胃朊酶、木瓜酶。

4 component   

n.组成部分，成分，元件；adj.组成的，合成的

参考例句：

• Each component is carefully checked before assembly.每个零件在装配前都经过仔细检查。
• Blade and handle are the component parts of a knife.刀身和刀柄是一把刀的组成部分。

5 entirely   

ad.全部地，完整地；完全地，彻底地

参考例句：

• The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
• His life was entirely given up to the educational work. 他的一生统统献给了教育工作。

6 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

7 high-tech   

adj.高科技的

参考例句：

• The economy is in the upswing which makes high-tech services in more demand too.经济在蓬勃发展，这就使对高科技服务的需求量也在加大。
• The quest of a cure for disease with high-tech has never ceased. 人们希望运用高科技治疗疾病的追求从未停止过。