在一定条件下,萘可以和硝酸、硫酸和混合酸发生硝化反应,生成二硝基物,它是1,5-二硝基萘和1,8—二硝基萘的混合物。后者可溶于质量分数大于98%的硫酸,而前者不能。利用这一可以将这两种异构体分离。将上述硝化产物加入适量的98.3%硫酸,充分搅拌,用耐酸漏斗过滤,欲从滤液中得到固体1,8—二硝基萘,应采用方法是A.对所得的滤液蒸发、浓缩、冷却、结晶 B.向滤液中缓缓加入水后过滤C.向滤液中加入Na2CO3溶液后过滤 D.将滤液缓缓I like ________ , but I don't like ________ this afternoon. It is too cold.
A. to swim; to swim
B. swimming; swimming
C. to swim; swimming
D. swimming; to swim