重點講解：
1. step up 增加(數量等);提高(速度、強度等)；
Fears of a possible faltering of the recovery forced the government to step up stimulus spending.
對經濟復蘇可能步履維艱的恐懼，迫使政府加大了刺激性支出的力度。
2. preside over 負責；主持；
Who preside over the meeting have not be decided.
這個會議要誰來主持還未決定。
3. bring forward 提出（觀點）；提交（議案）；
In order to settle increasing air traffic, ICO bring forward the concept of free flight.
為了解決日益增長的空中交通量，國際民航組織提出了自由飛行的概念。
4. run afoul of （與法律、規章等）相抵觸，有沖突；
His business methods were not entirely honest, and he soon ran afoul of the law.
他做生意的方法不很老實，不久就犯了法。