challengeable adj. 挑战性的；challenging v. 要求；质疑；反对；向…挑战。例句：She does not like anyone challenging her authority. 她不喜欢任何人挑战她的权威。
challenge的短语：accept a challenge释义：接受挑战例句：It is a wonderful challenge and we should always accept a challenge. 这是一个伟大的挑战，我们乐于接受这项挑战。