重点讲解：
1. when it comes to 谈到；涉及；
例句：Shelly can hold her own when it comes to bicycling.
一涉及到骑自行车，谢利就不会败给别人。
2. step up to the plate 开始行动；
例句：Every time you keep quiet and refuse to step up to the plate, you have one less chance to prove yourself.
每当你保持低调,不肯出面采取行动的时候，你就少了一次证明自己的机会。
3. prop up 支撑；维持；
例句：Intelligence and wisdom is the lever propping up the society.
聪明才智是支撑社会的杠杆。
4. turn around (使)复苏；(使)好转；
例句：’m sure our housing sale will turn around next month.
我相信我们的住房销售下个月肯定会好转。
