Snowflakes are so diverse. In fact, meteorologists had an international classification system for them.

雪花类型非常多样。实际上，气象学家对它们有一个国际分类系统。

The World Health Organization last year included burnout in its international classification of diseases as a widespread " occupational phenomenon" characterized by depletion or exhaustion, negative feelings or cynicism about one's job, and reduced effectiveness at work.

世界卫生组织去年在其国际疾病分类中将倦怠列为一种普遍的“职业现象”， 其特征是精疲力尽、对工作产生负面情绪或愤世嫉俗，以及工作效率下降。