Throughout the world__________advance has been made in science and technology is due to education which brings forth knowledge, creation and inventions.

A．whoever

B．whatever

C．what

D．that

（1）硬水给生活和生产带来了很多麻烦，常用______的方法来降低水的硬度．

（2）请写出日常生活中节约用水的两条具体措施：______；______．