Section C
A buld-it-yourself solar still（蒸馏器） is one of the best ways toobtain drinking water in areas where the liquid is not readily available.Developed by two doctors in the U.S. Department of Agriculture, it’s anexcellent water collector. Unfortunately, you must carry the necessaryequipment with you, since it’s all but impossible to find natural substitutes.The only components required, though, are a 5’×5’ sheet ofclear or slightly milky plastic, six feet of plastic tube, and a container—perhaps just a drinking cup — to catch the water. These pieces can be foldedinto a neat little pack and fastened on your belt.
To construct a working still, use a sharpstick or rock to dig a hole four feet across and three feet deep. Try to makethe hole in a damp area to increase the water catcher’s productivity. Place your cup in the deepestpart of the hole. Then lay the tube in place so that one end rests all the wayin the cup and the rest of the line runs up — and out — the side of the hole.
Next, cover the hole with the plastic sheet,securing the edges of the plastic with dirt and weighting the sheet’s center downwith a rock. The plastic should now form a cone(圆锥体) with 45-degree-angled sides. The low point of the sheet must becentered directly over, and no more than three inches above, the cup.
The solar still works by creating agreenhouse under the plastic. Ground water evaporates (蒸发) and collects on the sheet untilsmall drops of water form, run down the material and fall off into the cup.When the container is full, you can suck the refreshment out through the tube,and won’t have to break down the still every time you need a drink.
What do we know about the solar still equipment from the first paragraph?
细节理解题。根据题干答案定位在第一段最后一句话。These pieces can be folded into a neat little pack and fastened on your belt.译文“这些设备可以折叠成一个干净整洁的包裹，并且可以系到你的腰上。”所以推断出，这是便携式的。本题的难度在于词汇。delicate“易坏的”。complex复杂的.
What does the underlined phrase “the water catcher” in paragraph 2 refer to?
词义推断题。To construct a working still, use a sharp stick or rock to dig a hole four feet across and three feet deep. Try to make the hole in a damp area to increase the water catcher’s productivity.译文“为了建造一个蒸馏器，需要用棍子或石头挖一个四米宽，三米深的坑。为了增加它的聚水能力要把坑挖在潮湿的地方。”the water catcher直译为“捕水器，抓水的工具”而纵观全文，蒸馏器的功能就是帮助缺水的地方收集水。所以选择B。
What’s the last step of constructing a working solar still?
细节理解题。根据题干答案定位在Next, cover the hole with the plastic sheet, securing the edges of the plastic with dirt and weighting the sheet’s center down with a rock。最后一个步骤就是把石头放在塑料板的中央增强重力。
When a solar still works, drops of water come into the cup form.
Ground water evaporates (蒸发) and collects on the sheet until small drops of water form, run down the material and fall off into the cup.译文“地表水蒸发后，在塑料板上凝聚形成水滴，然后顺流落入杯中。”所以落入杯中的水滴是在塑料板上形成的。