电能质量的指标是() ["电流和电压","有功和无功","频率和电压","电流和频率"]
用活性炭管采集工作场所空气中乙酸乙酯,用气相色谱法-氢焰离子化检测器检测,最常用的解吸溶剂为() ["CS2<\/sub>","C2<\/sub>H5<\/sub>OH","CHCl3<\/sub>","CH3<\/sub>OH","CH2<\/sub>Cl2<\/sub>"]
女性,27岁,红细胞计数值2.7×1012/L,血红蛋白60g/L,白细胞及血小板正常,血涂片检查可见红细胞呈小细胞低色素性改变,网织红细胞1.5%。可初步诊断为() ["急性失血性贫血","缺铁性贫血","再生障碍性贫血","溶血性贫血","巨幼细胞性贫血"]
图书馆学的研究方法有哪些?
碱性最强的生物碱是() ["伯胺生物碱","叔胺生物碱","仲胺生物碱","季铵生物碱","酰胺生物碱"]
完全失业