题目

A Brown University sleep researcher has some advice for people who run high schools: Don’t start classes so early in the morning. It may not be that the students who nod off （打盹）at their desks are lazy. And it may not be that their parents have failed to enforce (确保) bedtime. Instead, it may be that biologically these sleepyhead students aren’t used to the early hour. “Maybe these kids are being asked to rise at the wrong time for their bodies,” says Mary Carskadon, a professor looking at problem of adolescent sleep at Brown’s School of Medicine. Carskadon is trying在100g碳不完全燃烧所得气体中，CO占1/3，CO2占2/3，且C（s）+1/2O2（g）＝CO（g） △H＝-110．35kJ/mol；CO（g）+1/2O2（g）=CO2（g）;△H=-282．57 kJ/mol，与这些碳完全燃烧相比，损失的热量是A．392．92kJ B．2489．44kJC．3274．3kJ D．784．92kJ