His wife says that he was more frugal in his youth than later years.(2003年中国人民大学考博试题)

单项选择题As one of the youngest professors in the university, Miss King is certainly on the ______ of a brilliant career.(2013年北京航空大学考博试题)

单项选择题We are convinced that we are on the ______of an important discovery.(2004年上海理工大学考博试题)