本讲为2007年上半年新的教学内容，请对照教材听录音！
 
  It is a good idea that we will have a picnic at the weekend.
  It is a good idea that Mr. Frank offered us.
  Many of the ideas which scientists tell us have on foundation have to do with mixtures of food.
  The reason was given
  The reason given by a professor is wrong. The reason which was given by a professor is wrong.