重點講解：
1. a waste of
浪費；
eg. It is a waste of time to listen to his insignificant talk.
聽他那些廢話純屬浪費時間b(AZiGoPZE2fcTH]。
eg. I've finished with gambling it's a waste of money.
我已經戒賭了——賭博完全是浪費錢財SQ!bMyyn%Xi。
2. set off
點燃；
eg. If you drop a lighted cigarette, you could set off a fire.
如果你把一根點燃的香煙掉在地上，就有可能引起火災A#noj3HZrdF。
eg. He likes to set off firecrackers during Diwali.
他喜歡在排燈節放鞭炮fV.(i[;[HZ3adAx;eQ0。
3. lead to
招致；致使；導致；
eg. There are recognised black spots in marriages which can lead to trouble.
婚姻中有一些公認的容易引發問題的雷區Ax+TABz!P=N%QMS)。
eg. Early success may lead to megalomania.
少年得志可能導致妄自尊大Q~2v#bJkJHygQ4Q。