1. 這位拳擊冠軍深曉拳擊中投機取巧的所有竅門，他知道很多傷害對手并使其亂陣腳的方法。
   The champion knows all the tricks of the boxing trade; he knows many ways to hurt his opponent and to get him mixed up.
2. 竅門就在於瞄準時須屏住呼吸。
   The trick is to hold your breath while you aim.
3. 鎖這門要有竅門，得用些時間才能學會。
   There's a knack in/to locking this door which takes a while to master.
4. 你取得成功有什麼竅門？
   What is your recipe for success?

門的英語翻譯：