新陳代謝the new replaces the old (metabolism in biology)
信口開河empty promises;to talk off the cuff
心口如一to be frank and unreserved;honest and straightforward (lit. heart and mouth as one)
欣欣向榮luxuriant growth;flourishing;thriving
心直口快frank and outspoken;to say what one thinks
興高采烈happy and excited;in high spirits;in great delight
興致勃勃to become exhilarated;in high spirits;full of zest
懸崖峭壁sheer cliffs and precipitous rock faces
雪上加霜to add hail to snow;one disaster on top of another;to make things worse in a bad situation
雪中送炭timely assistance (lit. to send coal during snow)