用烟火点试法鉴别余气时，发生（）现象，则为可燃气体。
A、火焰呈红色并发出"噗噗"轻度爆鸣声
B、剧烈燃烧并呈现光亮
C、条香熄灭
参考答案：A
—I have a toothache.
—You should _______. [ ]
A. Lie down and rest
B. drink some tea with honey
C. see a dentist
D. drink hot water
3481×5.2+4.8×3481的值是( )
A．31410
B．44610
C．34810
D．28610
