单选题 What does the author mainly discuss in this passage?
[A] How to avoid car crash. [C] How to educate children properly.
[B] How to design safer baby equipment. [D] How to properly secure children in the ear.

【正确答案】 D
【答案解析】主旨题。文章指出，造成儿童车祸死亡的一大原因是他们没有受到适当的保护，文章还介绍了如何根据儿童的年龄、体重、身高等正确使用安全座椅或安全带以保护他们在车中的安全，所以D正确。