prep2-5,作了5次都是错的

topdownload

Microscopic plants called algae grow inside the top layer of sea ice in the Antarctic if enough sunlight reaches that layer of ice and enough seawater, which contains nutrients, reaches that layer after splashing onto the surface.  Even though moderate snow cover reduces the sunlight that filters into the top layer, sea ice with moderate snow cover typically contains even more algae in the top layer than does sea ice with less snow cover.

 

Which of the following, if true, most helps to explain the apparent discrepancy?

 

(A) As the weight of accumulated snow forces ice lower in the water, more seawater splashes onto the surface and seeps through the snow.

(B) Seawater in the Antarctic often contains higher concentrations of nutrients than does seawater in more temperate regions.

(C) As the air temperature around sea ice decreases during the winter, the likelihood decreases that snow will fall and thus add to any existing snow cover.

(D) The nutrients on which algae rely are common in seawater throughout the Antarctic.

(E) More sunlight filters through a layer of ice than through an equally thick layer of snow.

 答案是a,百思不得其解,哪位高手能帮忙解答下

jeannefq

Microscopic plants called algae grow inside the top layer of sea ice in the Antarctic if enough sunlight reaches that layer of ice and enough seawater, which contains nutrients, reaches that layer after splashing onto the surface.  当有充足的阳光和富营养的海水的时候,海藻就能在冰的表层生长.Even though moderate snow cover reduces the sunlight that filters into the top layer, sea ice with moderate snow cover typically contains even more algae in the top layer than does sea ice with less snow cover.即使雪减少了阳光,但有雪覆盖的冰上还是比较少覆盖的冰上拥有更多的海藻.

我的理解是,因为要有海藻的形成是需要同时有两个条件的.被雪覆盖,无论是多还是少,都阻碍了阳光.这是一个条件,两者是平等的.那么要有区别只可能在另一个条件,就是海水上面.而A刚好给出了越重就有越多海水的解释.

(A) As the weight of accumulated snow forces ice lower in the water, more seawater splashes onto the surface and seeps through the snow. 因为重量关系,有更多的海水进来.

(B) Seawater in the Antarctic often contains higher concentrations of nutrients than does seawater in more temperate regions. 和温带去比海水,无关

(C) As the air temperature around sea ice decreases during the winter, the likelihood decreases that snow will fall and thus add to any existing snow cover. 文中都没有讲到温度

(D) The nutrients on which algae rely are common in seawater throughout the Antarctic. 这个也是无关的吧

(E) More sunlight filters through a layer of ice than through an equally thick layer of snow. 这个是不是说冰比雪更容易吸收阳光?

讨论讨论啊,呼唤NN...

topdownload

但是a说的是weight越lower,水越多,这样不是与题目结论矛盾吗? As the weight of accumulated snow forces ice lower in the water

dudulee

原文说这种algae生长的2个条件是1。充足的阳光 2。充足的海水。

然后说有适当的积雪的冰虽然阻挡了一部门阳光，但是却长着更多的algae。我做这道题目的时候马上想到的是积雪间接的提供了2个条件中的一个，阳光已经说过了，剩下的就是充足的海水。而a选项说的就是积雪将冰面往水下压，那么更多的海水流过了冰面跟积雪。也就是提供的充足的海水。

bobbie627

以下是引用topdownload在2007-8-18 16:52:00的发言：

但是a说的是weight越lower,水越多,这样不是与题目结论矛盾吗? As the weight of accumulated snow forces ice lower in the water

对啊，冰上积雪越多，（包含积雪在内的）冰的重量就越重，那么冰面就会比没有积雪时更接近海水平面，于是会有更多的海水溅到冰面上来啊

sinowen

和楼主很相似的经历，发现许多题目必须要去理解，才可以避免重复出错。

apostlep43

A

追梦爱我

真佩服楼主，会做5遍

lijiahui0422

不是weight lower  而是weight forces ice lower

蔬菜小丸子

没人？