下面的关于计算机图形和图像的叙述中，正确的是 ( )A．图_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题单项选择题

下面的关于计算机图形和图像的叙述中，正确的是 ( )

A．图形比图像更适合表现类似于照片和绘画之内的有真实感的画面

B．一般说来图形比图像的数据量要少些

C．图形比图像更容易编辑、修改

D．图像比图形更有用

答案

参考答案：C

解析：图形表示方法与图像表示方法有许多本质的区别。从数据量方面：图形的数据量很小，图像的数据量很大；从可编辑性方面：图形的可编辑性很好，图像的可编辑性较差；从3D景物表现能力方面：图形能准确的表示3D景物，图像的3D信息已部分丢失；从自然景物表现能力方面：图形比较困难表现自然景物，图像很容易表现自然景物；从视图生成能力方面：图形能生成多个视图，图像只能生成1个视图；从试图生成的复杂度方面：图形需要大量计算，图像的计算比较简单。所以选项C的说法是正确的。

单项选择题 A1/A2型题

X线影像信息的传递，错误的是（）

A.被照体作为信息源

B.X线作为信息载体

C.经显影处理形成可见密度影像

D.第一阶段的信息传递取决于胶片特性

E.X线诊断是X线影像信息传递与转换的过程

完形填空

It is interesting how NASA(美国航天航空局) chose their astronauts for landing them on the moon. They chose men   36  the ages of twenty and thirty-five. There were about fifty of them. Some were   37  air pilots, and 38  were scientists with two or three degrees. NASA telephoned each man they were going to choose, told him the plans and the   39  they might get into. They then asked him if he was willing to be trained as an astronaut, “How could any man   40  such an exciting job?” One of them said, “Dangerous? Of course. It’s dangerous   41  most exciting.”
The health and physical condition of the people was, 42 , very necessary. Only those in very good health and physical condition were   43 .
While being trained to be astronauts, they went through many   44 . They studied the star and the moon, and they also studied geology, the science of rocks. This was necessary   45  astronauts would have to look for rocks on the moon. They would try to find rocks which might help to tell the   46  of the moon. They were all   47  to fly in helicopters. There helicopters landed straight down to give them some   48  of the way the spaceship would actually land on the   49 . They were also taught the known facts about the   50  in space. They learnt about all the scientists and engineers who   51  spaceships. They visited the   52 where spaceships were repaired. They learnt how every   53  of a spaceship and its instruments work. They also learnt every detail of ground-control   54 .
In a word, to be chosen as astronaut, one must be in good   55 , well-informed in science and good at piloting.

A．experienced

D．even though