They've started giving really responsible positions to people who are actually still wet behind the ears.他们已经开始把责任重大的岗位给一些还乳臭未干的人了。Take him seriously; he is not the suckling he was two years ago.不要小看他；他已不是两年前的那个乳臭未干的人了。He was a callow youth when he joined the newspaper.他进报社时还是个乳臭未干的小伙子。