本讲为2007年上半年新的教学内容，请对照教材听录音！
   
  1.It is known that diamonds are the hardest substance.
  2.Most diamonds today are not found in stream beds, but mined from rock formation deep in the earth.
  3.Diamonds do not look impressive when they are first mined.
  4.He has no persistence in doing anything.
  5.The eruption\explosion of active volcano is a kind of terrible natural phenomenon.
  Hand in ---- hand out
  1.                   please sort out the things you want to keep and throw everything else away.
  2.                   The price of the elevator is somewhat higher than expected.
  3.                   These designs are very popular with young people.
  4.                   He stopped writing because his pen ran out of ink.
  5.                   Experienced people can tell the real one immediately.
  Fog---foggy
  Set aside
  Enlarge                                               
  Confuse---confusing---confused
  Melon-seeds
  observation
  Seafood
  Latter
  Dweller
  Narrow
  In broad sense
  Wide
  Close---closed
  Be happy with
  Happen---occur
  Sheep live on grass.
  Two thirds
  one third
  Two fifths
  Dig---dug---dug
  The climate of Beijing is much drier than that of Shanghai.