雪的形成与作用。

Hints：
two and one-half centimeters
Earth's atmosphere

翻译：龙猫08
校对：OFELIA1030
组长：jushua
答疑：凌云飞雪
When snow crystals stick together, they produce snowflakes. Snowflakes come in different sizes. As many as 100 crystals may join to form a snowflake larger than two and one-half centimeters. Under some conditions, snowflakes can form that are five centimeters across. Usually, this requires near-free…
雪晶粘在一起形成了雪花。雪花的大小各有不同。100个雪晶结成一个大于2.5厘米的雪花。在某些情况下，雪花可以达到5厘米大小。通常这种情况需要接近冰点的温度，微风和地球大气活动变化。 雪包含的水分远低于雨水。2.5厘米大小的雨水所含的水分大约和15厘米的湿雪一样。76厘米的干雪所含水分相当于2.5厘米的雨水所含的水分…