1.top-selling 畅销的

例句：Radio 1's playlist is dominated by top-selling youth-orientated groups.
广播一台主要播放一些面向年轻人的乐团所演唱的畅销曲目,_=F-9.*hfYHCx)#J。

2.heart attack 心脏病

例句：He died of a heart attack brought on by overwork.
他死于过劳引起的心脏病发作3DUOsW61k*WsGVkB。

3.be essential to 对..重要

例句：It will be essential to establish how the money is being spent.
查清楚这笔钱将作何用途至关重要fJg3~v~o(ddR。

4.work on 从事于

例句：The scientists are still working on inventing new methods of reaching outer space.
科学家们仍致力于发明到达外层空间的新方法!TgBnJdtJyhm!X;2e。