山头和洼地的等高线相似，判别的方法为（） ["以等高线的稀疏程度为标准判断","以等高线高程注记为标准判断","以等高距为标准判断","以等高线平距为标准判断"]
以很高的死亡率和很高的出生率以及很低的自然增长率为特征的人口增长模式被称为（） ["原始型","由原始性向传统型的过渡阶段","现代型","传统型"]
下列选项不属于股金管理业务流程的是（）。 ["签订股金转让协议","转让","股金主子账户销户","配发股权证"]
赠送样品作为一种销售促进方式具有哪些特点？
How should you signal the crane operator to raise the boom and lower the load?（）. ["Extend arm with the palm down and and hold this position rigidly","Place both fists in front of the body with the thumbs pointing outward each other","Clasp hands in front of you body","Extend arm with the thumb pointing up, and flex the finger s in and out for as long as the load movement is desired"]
叶酸的主要作用是什么？
