drop a courtesy

例句：

1. 1. The temperature droppedsignificantly after the storm.
   暴风雨过后，温度显著下降。
2. 2. The drop in oil prices hasaffected our budget.
   油价下跌影响了我们的预算。
3. 3.She dropped her phone into the river tosave it from water damage.
   她把手机扔进河里，以防它被水损坏。