单项选择题
A．The Greatest Killer in the West B．Heart Disease: Treat or Prevent C．Modern Technology and Heart Surgery D．Heart Surgery: Advantage and Disadvantages
A．more money should be spent on the prevention of heart disease B．heart surgery has helped most patients improve their conditions C．modern technology has made heart surgery more risky than before D．the public have known a great deal about the causes of heart disease
A．lengthening the existing 53-kilometer subway is among the 50 large projects B．the length of the subway will be up to 135.25 kilometers in 2005 C．a 40.5-meter-long line will be added to Beijing's first light railway D．a 70-meter-wide green belt will supply us with enough water