a skeleton crew的用法和样例：
- Only a skeleton crew was needed while the ship was tied up in dock.
- Only a skeleton crew are needed while the ship is tied up in dock.
- Only a skeleton crew is needed while the ship is tied up in dock.
- Slow sales of the sports cars means current stock will last at half-production with just a skeleton crew on duty.
- A skeleton crew of ILM cameramen traveled to Guatemala to film the handful of scenes required.