全世界每年因生锈损失的钢铁，约占世界年产量的四分之一。铁与氧气、水等反应生成铁锈，铁锈的主要成分是什么？请你谈谈生活中观察到的保护钢铁制品的两条有效措施。

It can be inferred from the passage that electric response audiometry would be especially recommended for_______.

A．a three-year-old girl who has an earache

B．an old man who cups his ear to ear

C．a young child who does not talk

D．a rock musician who plays the drums