A sure test for would-be heroes is what or whom do they serve?

对那些想成为英雄的人来说，找到服务的对象或目的，是一个必经的考验。

youdao

"I thought that sooner or later one thing was sure to happen: The first real test once he was through school would ruin him.

VOA: special.2009.01.03

Then they test you to make sure that you have adequate protection, and some people need an additional shot after that.

然后医生会检测以确定你已获得了保护,有些人在测试完后需要再打一针

耶鲁公开课 - 生物医学工程探索课程节选

Don't worry. I'm sure you will pass the next test.

别担心。我相信下次你肯定能通过的。

I'm sure 课堂 - SpeakingMax英语口语达人

It is a sure test of false criticism that it sets out precepts which would deny the possibility of the works that it describes.

ECONOMIST: Literary criticism

The smart thing to do is make sure you test drive before you buy.

FORBES: Test Drives

Then, make sure the test takes into account the skills and personalities the job requires.

CNN: Testing times in the search for talent