over作为前缀表示什么意思

　　Nurses complain of being overworked and underpaid.

　　护士抱怨工作劳累过度而报酬过低。

　　She overworks her staff.

　　她让员工过度劳累。

　　He died of a heart attack brought on by overwork.

　　他死于过劳引起的心脏病发作。

　　He's overworking and has got a lot on his mind

　　他工作太累，而且非常操心。

　　'Ecological' has become one of the most overworked adjectives among manufacturers of garden supplies.

　　“生态的.”这个词已经成为园艺产品生产商用得最滥的形容词之一。