求助2018版og

熊孩子雷包

感觉A也符合要求，为什么不选A
求助各位大神啊啊啊啊啊啊

spicytaco

楼主应该受到批评啊...在几个关键字就可以搜出原题的..楼主这么贴图片好费事，别人也不方便看呢
帮你贴出来

When there is less rainfall than normal, the water level of Australian rivers falls and the rivers flow more slowly. Because algae whose habitat is river water grow best in slow-moving water, the amount of algae per unit of water generally increases when there has been little rain. By contrast, however, following a period of extreme drought, algae levels are low even in very slow-moving river water.

Which of the following, if true, does most to explain the contrast described above?

(A) During periods of extreme drought, the populations of some of the species that feed on algae tend to fall.

(B) The more slowly water moves, the more conducive its temperature is to the growth of algae.

(C) When algae populations reach very high levels, conditions within the river can become toxic for some of the other species that normally live there.

(D) Australian rivers dry up completely for short intervals in periods of extreme drought.

(E) Except during periods of extreme drought, algae levels tend to be higher in rivers in which the flow has been controlled by damming than in rivers that flow freely.

spicytaco

Because algae whose habitat is river water grow best in slow-moving water, the amount of algae per unit of water generally increases when there has been little rain.
首先上面水流慢，正适合 algae增长...所以正常情况下少雨时候， algae就会增加



(A) During periods of extreme drought, the populations of some of the species that feed on algae tend to fall.
极端干旱时期，以algae为主食的物种数量会下降

这不就等于在说algae应该增加才对啊，而问题是however, following a period of extreme drought, algae levels are low even in very slow-moving river water. 人家问你为什么 algae为什么会低？


(D) Australian rivers dry up completely for short intervals in periods of extreme drought.

解释很清楚了...本来 在少雨季节， algae应该会增加，可现在却出现了河流完全干枯了，所以 algae才会下降

熊孩子雷包

spicytaco 发表于 2018-12-2 15:24
Because algae whose habitat is river water grow best in slow-moving water, the amount of algae per u ...

不好意思啊我刚开始学刚开始用这个论坛不太了解规则，以后再发帖的时候一定会注意的，非常感谢了?真的非常感谢