perform的前缀为pre，后缀为form
例句
1、
The tasks had to be performed in a particular sequence.
这些任务必须按一定次序去执行。
2、
The manager decided to choose a responsible person to perform the task.
经理决定挑选一名有责任心的人来执行这项任务。
3、
This operation has never been performed in this country.
这个国家从未做过这种手术。
