学校进行了自上而下的课程改革，涵盖了所有年级的教学内容。

The school implemented a ___top-to-bottom curriculum reform, covering all grade levels.

我们进行了从上到下的系统检查，确保没有遗漏任何问题。

We conducted a ___top-to-bottom system check to ensure no issues were missed.