A:Get some sleep.
B:See a doctor.
C:Take some exercise.
读图,完成下列问题.
称取粗盐 →① →②BaCl2→③NaOH →④ →⑤过滤 滤液 →⑥适量盐酸 →⑦蒸发、结晶、烘干 精盐