重點講解：
1. get to the bottom of 找到…的真正起因；查尋到…的根；
例句：She got suspicious and decided to get to the bottom of it.
她起了疑惑，便決定弄個水落石出c*oileJ7&byIfcf!eh。
2. all of a sudden 突然地；出乎意料地；
例句：All of a sudden there was a terrific bang and a flash of smoke.
突然傳來驚天動地一聲響，還冒出一股煙Vh2us|=O,x1&8TLk。
3. keep up 保持；
例句：There will be a major incentive among TV channels to keep standards up.
將會有重大舉措鼓勵各電視頻道維持高標準nWCLbh=[b2toJiq。
4. in the first place 起初；一開始；
例句：It was a shooting star that propelled me into astronomy in the first place.
最初是一顆流星促使我從事天文學2dNrv;k2o1VoUIE_|mD。