a combined effort的用法和样例：
- After a combined effort by both teachers and students, they find out that the trouble was caused by TING.
- Japan's moral education is a combined effort made by both the school and the family, and has produced fruitful results in improving the quality of its people.
- Give your baby a combined surname?
- This is a combined offer on all or none basis.
- Final development reveals a combined image.