1、 They made vain attempts to reach the mountaintop、他們幾次徒然嘗試想攀登山頂。
2、 The police tried in vain to break up the protest crowds、警察企圖驅散抗議的人群，但沒(méi)有成功。
3、 She's very vain about her good looks、她為她那好的容貌而自負。
4、 He is vain of his speech、他對自己的發(fā)言很得意。
5、 She is vain and extravagant、她既愛(ài)虛榮又奢侈。