What is a convenient and effective system of examining the body of an injury victim?（） ["Check the corresponding (left versus right) parts of the body","Watch the patient's eyes as you probe parts of the body","Look for discoloration of the patient's skin","Look for uncontrolled vibration or twitching of parts of the body"]
简述氢气冷却系统的开车步骤。
在焦炉加热中，实际供给的空气量与理论空气量之比等于（）为宜。 ["0.75","1.0","1.25","1.5"]
采用高压脱水方法，强化了原油乳化液水滴的（）和合并过程。 ["无碰撞","极化","密度差","沉降速度"]
关于DNA与同源重组的关系，下列说法正确的是哪一项？（） ["同源重组过程中，一定发生DNA链的断裂","DNA链的断裂，一定诱发同源重组","同源重组发生于同源染色体之间，而不是发生于相同的DNA序列之间","DNA序列相同与否，不会显著影响同源重组的效率","同源重组只发生于基因之间的DNA区段，而不会发生在基因内部"]
简述根据经营商品范围划分批发商类别，根据提供服务范围划分批发类别。
