44 Which of the following is NOT mentioned as a traditional source of water?
(A) Dams
(B) Snow
(C) Rivers
(D) Groundwater

With the increasing water shortages and growing water conflicts衝突；分歧, some people start to ask: why don’t we get our drinking water from the ocean?

The problem is that the desalination海水淡化 of water requires a lot of energy.

Salt dissolves溶 very easily in water, forming（使）出現，（使）形成 strong chemical bonds聯繫, 紐帶；聯繫；關係, and those bonds聯繫, 紐帶；聯繫；關係 are difficult to break.

Energy and the technology to desalinate海水淡化 water are both expensive.

There are environmental costs of desalination海水淡化 as well也.

Sea life can get sucked吸, 吮, 吸取 into desalination海水淡化 plants生物體, 植物, killing small ocean creatures, and upsetting令人心煩意亂的，令人苦惱（或憤怒）的 the food chain.

Also, there’s the problem of what to do with the separated salt.

Pumping this super-salty water back into the ocean can harm local aquatic水棲的；水生的 life.

Reducing減少；減小；降低 these impacts衝擊（力）；撞擊（力） is possible, but it adds to the costs.

Despite the economic and environmental hurdles問題, 障礙，難題, desalination海水淡化 is becoming increasingly attractive as we run out用完；耗盡；賣光, 被耗盡；被用完 of water from other sources.

We are over-pumping抽水 groundwater, we have already built more dams（尤指旨在蓄水的）水壩 than we can afford economically and environmentally, and we have tapped nearly all of the accessible rivers.

Far more must be done to use our existing water more efficiently, but with the world’s population escalating（使）增強；（使）擴大 and the water supply dwindling減小；降低, the economic tide潮流、變化 may soon turn in favor of desalination海水淡化.