GRE OG上72页的阅读的第2题求解呀！

eveshshUID: 3638760

  题目：

For hot desert locations with access to seawater, a new greenhouse design generates freshwater and cool air. Oriented to the prevailing wind, the front wall of perforated cardboard, moistened and cooled by a trickle of seawater pumped in, cools and moistens hot air blowing in. This cool, humidified air accelerates plant growth; little water evaporates from leaves. Though greenhouses normally capture the heat of sunlight, a double-layered roof, the inner layer coated to reflect infrared light outward, allows visible sunlight in but traps solar heat between the two layers. This heated air, drawn down from the roof, then mixes with the greenhouse air as it reaches a second seawater-moistened cardboard wall at the back of the greenhouse. There the air absorbs more moisture, which then condenses on a metal wall cooled by seawater, and thus distilled water for irrigating the plants collects.

It can be inferred that the greenhouse roof is designed to allow for which of the following?
A  The avoidance of intense solar heat inside the greenhouse
B  The entry of sunlight into the greenhouse to make the plants grow
C  The mixture of heated air with greenhouse air to enhance the collection of moisture

知道A对应：but traps solar heat between the two layers；
但是B的前半句对的，但是后半句的to make the plants grow怎么来的呀？
C就更觉得不对了，这个mixture的过程不是在cardboard wall 进行的吗？怎么就和roof有关系呢？

eveshshUID: 3638760

大神求解呀！！三天了。。。都木有人

wfxmfwjwUID: 3582171

eveshsh 发表于 2015-9-2 16:41
大神求解呀！！三天了。。。都木有人

This heated air, drawn down from the roof, then mixes with the greenhouse air as it reaches a second seawater-moistened cardboard wall at the back of the greenhouse.
应该是由roof引发的连续过程
to make the plants grow应该是常识

eveshshUID: 3638760

wfxmfwjw 发表于 2015-9-2 16:46
This heated air, drawn down from the roof, then mixes with the greenhouse air as it reaches a se ...

好像有点懂了，还能这样推。。。谢谢！