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举一反三
【单选题】下列实验方案或操作中，正确的是（ ）
A.
用稀硫酸除去铁粉中的铜粉
B.
用稀盐酸洗涤试管内壁的油污
C.
实验时多取的白磷可以放回原瓶
D.
按溶解、过滤、洗涤、蒸发结晶的操作顺序可以分离氯化钾、二氧化锰的混合物
【单选题】Lorries are responsible for over half of all cyclist deaths in London, a third across the UK as a whole, 43% of cycling fatalities in Belgium and 38% in the Netherlands. In all, about 1, 000 people di...
A.
incomprehensible
B.
indifferent
C.
negative
D.
objective