—There must be a dozen paper clips in these drawers but I can’t find one when I need one. —Keep looking .is sure to turn up. A.One B.It C.That D.This 答案:A one为代词,代指想找的one of the paper clips,为不特定的一个,而it/that/this均指代前文出现的同一事物。 工业纯碱中常常含有NaCl、等杂质。为测定某工业纯碱的纯度。设计了如图实验装置。依据实验设计,请回答:(1)仪器D的名称是______________;装置D的作用是______________________。(2)若不考虑操作、药品及其用量等方面的影响,该实验测得结果会___________(填“偏高”、“偏低”,“无影响”)。