问答题The second most important constituent of the biosphere is liquid water.This can only exist in a very narrow range of temperatures, since water freezesat 0℃ and boils at 100℃ This is only a tiny range compared with the low tem-peratures of some other pl

The second most important constituent of the biosphere is liquid water.This can only exist in a very narrow range of temperatures, since water freezesat 0℃ and boils at 100℃ This is only a tiny range compared with the low tem-peratures of some other planets and the hot interior of the earth, let the tem-　　　1．_______perature of the sun. As we know, life would only be possible on the face of a　　 　 2．_______planet had temperatures somewhere within this range.　　　　　　　　　　　　　　　　 3．_______　　The earth’s supply of water probably remains quite fairly constant in　　　　　 4．_______quantity. A certain number of hydrogen atoms, which are one of the mainconstituents of water, are lost by escaping from the atmosphere to out space,　　　　5．_______but they are probably just about replaced by new water rising away from the　　　　　6．_______depths of the earth during volcanic action. The total quantity of water is notknown, and it is about enough to cover the surface of the globe to a depth of　　　　7．_______about two and three-quarter kms. Most of it—97%—is in the form of the saltwaters of the oceans. The rest is fresh, but three quarter of this is in the form of 8．_______ice at the Poles and on mountains, and cannot be used by living systems when　　 　　9．_______melted. Of the remaining fraction, which is somewhat fewer than 1% of the　　　 　　10．_______whole, there is 10-20 times as much stored as underground water as is actual-ly on the surface. There is also a minor, but extremely important, fraction ofthe water supply which is present as water vapour in the atmosphere.欢迎使用ueditor!