燃灯法在灯上燃烧无烟石油产品时，对含硫量在0.05％以下的低沸点产品，注入量为（）mL.
A.1.5~3
B.4~5
C.3~4
D.5~6
参考答案：B
They ________ to enter the building by the back door; however, the front door was locked.
A．are supposed
B．aren’t supposed
C．weren’t supposed
D．were supposed
安全态度教育不包括下列哪一项内容（）
A、基本安全技术知识
B、法规教育
C、安全思想教育
D、安全生产方针政策教育
