Question

D

A buld-it-yourself solar still（蒸馏器） is one of the best ways to obtain drinking water in areas where the liquid is not readily available. Developed by two doctors in the U.S. Department of Agriculture, it’s an excellent water collector. Unfortunately, you must carry the necessary equipment with you, since it’s all but impossible to find natural substitutes. The only components required, though, are a 5’ 5’ sheet of clear 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 folded into a neat little pack and fastened on your belt.

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. Place your cup in the deepest part of the hole. Then lay the tube in place so that one end rests all the way in 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 down with a rock. The plastic should now form a cone(圆锥体) with 45-degree-angled sides. The low point of the sheet must be centered directly over, and no more than three inches above, the cup.

The solar still works by creating a greenhouse under the plastic. 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. 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.

1.What do we know about the solar still equipment from the first paragraph?

A.It’s delicate.                  B.It’s expensive.

C.It’s complex.                  D.It’s portable

2.What does the underlined phrase “the water catcher” in paragraph 2 refer to?

A.The tube                         B.The still

C.The hole                         D.The cup

3.What’s the last step of constructing a working solar still?

A.Dig a hole of a certain size                     B.Put the cup in place

C.Weight the sheet’s center down                  D.Cover the hole with the plastic sheet

4.When a solar still works, drops of water come into the cup form          .

A.the plastic tube                       B.outside the hole

C.the open air                          D.beneath the sheet

Answer

1.D

2.B

3.C

4.D

【解析】

1.推理判断题。根据第一段最后一句话These pieces can be folded into a neat little pack and fastened on your belt.可知制作蒸馏器的东西可以叠放在一个小包，系在腰间。说明制作蒸馏器的设备很轻便，portable表示“轻便的;手提的”，故选D。

2.推理判断题。根据Try to make the hole in a damp area to increase the water catcher’s productivity可知最好在潮湿的地方挖洞，以提高接水器的工作效率。接水器指的是在潮湿地方挖洞，在洞的底部放一个杯子，杯子上方用覆盖膜遮挡。整个装置构成接水器，而不是某个部分。这一题很容易错选D，但是退一步讲，就算在干燥的地方挖洞，杯子也可以接水，杯子接水的事实并不会因为周围的环境变化而变化，杯子的工作效率是不变的。故选B。

3.细节题。根据第三段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.可知最后一步是weighting the sheet’s center down with a rock“放一块石头在覆盖膜的中间，把它压下去”，故选C。

4.推理判断题。结合第四段中的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可知地下水蒸发，在覆盖膜上聚集起来直到形成小水滴落在杯子里。覆盖膜是在杯子上面的，水滴落入杯子里。所以水滴是凝聚在覆盖膜的下面。故选D。