promise to do

• 许诺做某事

promise to do的用法和样例：

例句

1. If everyone will promise to do his part, the plan will certainly he a success.
   如果每个人都保证尽到自己的责任，计划肯定会成功。
2. He gave his solemn promise to do better.
   他庄重地保证把事情办好。