为写作增加亮点的四六级作文常见开头:写作亮点
　　几种常见的开头法
　　(1) 主题句法：The appeal of advertising to buying motives can have both negative and positive effects.
　　The biggest safety threat facing airlines today may not be a terrorist with a gun, but the man with the portable computer in business class.
　　Believe it or not, optical illusion (错觉) can cut highway crashes.
　　(2) 问题法：Do you know how many people die from traffic accidents every 23 minutes?
　　Why does cream go bad faster than butter?
　　(3) 对比法：Some pessimistic e ...