alert|əˈlɜːt|1)adj.机敏的、2)v.警告
助记:alert(alarm clock闹钟)→警告
形近词:alien外国的,外星人alike同样的,同样地
真题例句:Consumers passionate about a product may create"earned"media by willingly promoting it to friends,and a company may leverage"owned"media by sending e-mail alerts about products and sales to customers registered with its Web site.