A:铁生锈
B:橡胶老化
C:酒精燃烧
D:食物腐烂
①澄清石灰水____;
②医疗消毒用高锰酸钾溶液(俗称紫药水)____;
③O.9%的氯化钠注射液(俗称生理盐水)____;
④硫酸溶液____.
— Which of the two magazines will you buy?
— I will take _______. ______ are useless to me.
完成填空