丙烯酰胺的半数致死量为()。
A.150-180ug/kg
B.250-280ug/kg
C.280-300ug/kg
D.300-320ug/kg
参考答案:A
— Can I help you with it?
— I appreciate your _______, but I can manage it myself.
A.advice
B.question
C.offer
D.idea
由于温度越高分子筛的吸附能力越差,可以采用升高床温的方法使原先吸附的杂质脱附。