required value

例句：

1. 1. The teacher required us to finish the homework before class.
   老师要求我们在上课前完成作业。
2. 2. The meeting was called for at 5 p.m.
   会议定于下午5点召开。
3. 3. He required a lot of time and effort to complete the project.
   他需要大量的时间和努力来完成这个项目。