A:汽油可溶解衣服上的油渍
B:纯碱可除去热水瓶中的水垢
C:洗洁精可清洗餐具上的油污
D:用肥皂水可检验硬水和软水
— What a touching love story! The main character Song Joongki in the Korean drama Descendants of the sun(太阳的后裔)acts very well.
— Really? When _______ it?
已知点A(k,4)在双曲线y=−4x上,则k的值是( )