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

   Part 3. PBS——a biodegradable plastic product.

  Keywords. plastic, new solution, biodegradable plastic, break down, PBS.
  Vocabulary. PBS, biodegradable, tableware, microorganism, enzyme, 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 replacement 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 enzymes, 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 component 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 entirely 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 celsius.
  While the Chinese product can retain its shape in up to 100 degrees.
  However, Ji Junhui says high-tech 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.
  原文地址:http://www.tingroom.com/lesson/step3000/step2/307143.html