大全-C-20

polaris16251

20.   Since the invention of digital readout, machine designers have rushed to replace conventional dials and gauges with digital units. Yet the digital gauge has drawbacks in some situations. Since it presents an exact numeric value, it must be decoded and analyzed by a human operator; its meaning cannot be read in an instantaneous scanning. An analog dial or gauge can be marked with red to alert the operator when a value is entering a danger zone; a digital gauge cannot. And it is difficult to tell whether a digital readout is increasing or decreasing over time, while the up or down movement of a pointer on an analog gauge can be quickly and easily observed.

The author of the passage above would probably recommend the use of digital gauge in cases when

I.     warning of a sudden rise or fall in value is needed

II.    an operator must read and interpret several gauges within a few seconds

III.   a precise numeric value is essential

(A) I only

(B) III only

(C) I and III only

(D) II and III only（B）

(E) I, II, and III

为什么不能选D呢,请NN指教

shell6688

As stated in the paragraph, "its meaning cannot be read in an

instantaneous scanning".  In other words, interpretation is impossible

within a few seconds.

youyiyoutian

I为何不对啊? 文中说了跟传统的刻度盘的量具比,电子读数的量具有两个缺点:1)因为它显示的是精确的数值,所以它必须由人来解码和分析,它数值所代表的意思就不能即时地被读懂. 2)传统的量具只要指针数值一进入危险区,操作员就知道了,而电子的不行.3)很难预测电子读数随时间的变动(上升或下降)趋势,而传统的量具却可以很快且很容易从指针的上下波动来预测变动趋势.

然后问题是怎么样电子读数的量具才能被推荐使用.我觉得解题思路应该解决电子读数量具的缺点入手啊?我怎么觉得除了I别的答案都不对呀? 还是我的思路有问题?

欢迎讨论!

stoner28

in order to understand the text , you'd better know the fallowing words :

dials刻度盘and gauges标尺

gonghao

个人理解

我的理解是，这道题问 在什么情况下作者会推荐这款devise?也就是说在没有那些
drawbacks的情况下。
III这个Devise只it presents an exact numeric value 文中有，devise 要求numeric .
I 这个是Sudden Rise而文中是increasing or decreasing over time,所以不一样.
II. 没有提到关于时间的问题!