standard blackbody source

例句：

1. 1.The standard for measuring the height of aperson is to measure from the floor tothe top of their head.
   测量一个人身高的标准是从地板到头顶的高度。
2. 2. The standardoperating procedure for this task is to followthe instructions carefully.
   完成这项任务的标准操作程序是仔细遵循指示。
3. 3. Thestandard for excellence in thisfield is unmatched byany other company.
   在这个领域内，这家公司的卓越标准无人能及。