语法总结
have sth. done
had the plane packaged / have the plane restored / have three of them rebuilt 都是“让别人去做”的结构。
相似句：
- We had the car repaired yesterday.
- She is going to have her house painted.
worth doing 的被动含义
worth rescuing 虽然用的是 doing，但意思是“值得被抢救”。
相似句：
- This old building is worth saving.
- The book is worth reading again.
过去完成时追溯原因
A colony of bees had turned... 用过去完成时来解释“为什么第四台发动机会完好无损”。
相似句：
- The river had flooded the road before we arrived.
- Someone had hidden the papers in the drawer.