私自: privately; secretly; without permission 短语和例子私自逃跑 escape secretly; 私自出售公物 sell public property without authorization; 本阅览室参考书不得私自携出。 no reference books are to be taken out of the reading r
涂改: alter; obliterate 短语和例子涂改文件 tamper with a document; 涂改无效 invalid if altered
私自买卖: buy and sell privatelybuy and sell without authorizationbuy or sell without authorization