司机操作采煤机，测尘点位置应在（）处。
A、司机工作地点
B、采煤机回风侧10～15米
C、作业人员回风侧3～5米
参考答案：A
When you do your homework,you should be __________.
[ ]
A. as careful as you could
B. as careful as possible
C. as carefully as you
D. as carefully as possible
以下不是食品加工、贮存中产生的有害物质的是（）。
A.苯丙芘
B.龙葵素
C.亚硝胺
D.组胺
E.鹿花毒蕈
