本讲为2007年上半年新的教学内容，请对照教材和练习册听录音！
  Be responsible for sth.
  Be irresponsible for sth.
  Drivers should be responsible for their passengers’ safety.
  Take responsibility for
  Ask sb. to do
  The librarian asked the students to replace the magazines after reading.
  Replace A with B
  They decided to replace iron and steel with plastics.
  They decided to substitute plastics for iron and steel.
   
  Biology
   
  The room is in a litter/mess.
   
   
  please don’t litter.
  generate
   
  paralyse   paralysis
  analyse   analysis
  a
  if they had…
  enable sb. to do