sell at auction; 拍卖
resell; 转卖
betray one's friend to obtain promotion 卖友求荣
exert all one's strength; do one's very best; exert oneself to the utmost 卖力气
like to show off one's merit 好卖功
牛津高阶第八版
美国韦氏词典
Dictionary.com
Free Dictionary
维基百科 (自由的百科全书)