a plaintive ditty的用法和样例：
- The qin was producing a plaintive tune.
- Suddenly a camel let out a plaintive ay, not far away.
- There was a plaintive wailfrom the sofa: "What about me?
- There was a plaintive wail from the sofa: "What about me?
- There was a plaintive cry from a crushed passenger in the rear of the bus.