秘密地When she thought no one was looking she opened the cupboard and took a few sweets on the sly. 當她認為沒人看見的時候, 她打開櫃子偷偷地拿了幾塊糖。She received letters, on the sly, from young men. 她暗中收到了一些男青年的來信。
偷偷地She is having an affair with her Japanese teacher on the sly. 她和她的日文老師偷偷有了戀情。He's been drinking whiskey on the sly for thirty years. 他暗中偷喝威士忌酒已有三十年了。
