食品中多环芳烃来源于（）、脂肪热聚和有机物焦化。
参考答案：熏烟
Guangzhou is making preparations for the 16th Asian Games ________ in November, 2010.
A．to be held
B．holding
C．held
D．being held
按五行属性分类，五行化土者是
A．生
B．长
C．化
D．收
E．藏
