安全生产法规定哪些生产经营单位不得从事生产经营活动？
参考答案：安全生产法规定，不具备安全生产条件的生产经营单位不得从事生产经营活动。
在Rt△ABC中，∠C=90°，AB=5，BC=3，以AC所在直线为轴旋转一周，求所得圆锥的侧面展开图的面积．
“safe speed” is defined as that speed where（）.
A.you can stop within your visibility range
B.you can take proper and effective action to avoid collision
C.you are traveling slower than surrounding vessels
D.no wake comes from your vessel
