【单选题】Including OTC drugs, how many pills does a person take during his/her life time?
【单选题】下列关于氢氟酸挥散法测二氧化硅量,说法不正确的是()。
A.
该方法适合于二氧化硅含量大于95%硅质耐火材料分析
B.
样品挥硅前需要经过高温灼烧,主要是为了消除样品中水分和有机物的干扰
C.
由于样品挥硅后残渣变为盐类物质,引起检测结果偏高,属于系统误差
D.
样品中二氧化硅含量越高,杂质越少,检测数据准确度越高
【单选题】How many pills should the patient take ______________?
【单选题】The doctor told him to be careful when taking sleeping pills because too many ______ could be.
【单选题】有关氢氟酸的下列说法错误的是
A.
氢氟酸蒸气溶于眼球内的液体中会对人的视力造成永久损害