1.The newspaper was directly challenging the government’s legitimacy.
报纸直接质疑政府合法性。
2.The new play poses some challenging questions.
出新戏提出些富有挑战性问题。
3.She performed the most challenging task without a mistake.
她毫无差错地完成最富有挑战性任务。
4.We have changed the course to make it more challenging.
我们改课程以使其更具挑战性。
5.His indecision caused him to lose the chance of a new challenging job.
他犹豫不决使他失去次得到新具有挑战性工作机会。
6.Take challenging composition courses (not just creative writing courses, but classes in journalism, technical writing, etc.) so that you can "speak" journalese, UNese, legalese, etc.