a boost to their morale的用法和样例：
- MLS owns the contracts of all their players and see Adu's move as a boost to their world standing.
- Yes, Tesla Troopers will still be able to charge nearby Tesla Coils for a boost to their efficiency.
- And because local currencies can't be banked away to earn interest, users keep spending it, providing a boost to their area's economy.
- It was a great boost to Mexican morale and pride.