[ S ] the layer of gases surrounding the earth at a height of between 50 and 100 kilometres:[ S ] the layer of gases surrounding the earth at a height of between 50 and 100 kilometres:
Extreme cold is needed to form ice in a dry environment like the mesosphere.
[ S ] the layer of gases surrounding the earth at a height of between 15 and 50 kilometres that is n[ S ] the layer of gases surrounding the earth at a height of between 15 and 50 kilometres that is n
平流层，同温层 The ash cloud rose 35km into the stratosphere.
