问题 单项选择题 A1/A2型题

与常规X线摄影技术相比,计算机X线成像的优点不包括以下()

A.X线剂量明显低于常规X线摄影技术

B.操作简单容易

C.可高保真储存、再现及传输图像

D.空间分辨力增高

E.存储空间明显减小

答案

参考答案:D

解析:计算机X线成像(CR)的主要优点.有:所需X线剂量明显低于常规X线摄影技术;与常规X线摄影设备不同的仅是用成像板替代胶片,发射部分无改变,故简单容易操作;具有多种图像后处理功能;可高保真储存、再现及传输图像;与胶片相比可省却大量的存储空间;可存储所有的信息,调出后仍然可进行不同的图像后处理。主要的缺点是空间分辨力较胶片低。故答案为D。

单项选择题
阅读理解

阅读理解。

    Kenyon Scudder once told me a story about his friend, Michael. Michael happened to be on a train sitting

next to a young man who seemed worried. Finally the young man told the friend that he was a prisoner

returning home from a faraway prison. His behavior had brought shame on his family, and they had neither

visited him nor written. He hoped, however, that this was only because they were too poor to travel and too

busy to write.

    When he was set free, he had written to tell them he wanted to go home. To make matters easy for them,

however, he had asked them to put up a signal for him when the train passed their little farm. If the family had

forgiven him, they were to put up a white ribbon in the big apple tree near the railway. If they didn't want him

to be back, they were to do nothing, and he would stay on the train, and go far away.

    As the train got near his hometown, his suspense became so great that he was afraid to look out of the

window. He asked Michael to watch for the big apple tree. They changed seats. In a minute, Michael put his

hand on the young convict's shoulder. "There it is," he said, his eyes filled with sudden tears. "It's all right.

The whole tree is white with ribbons."

1. According to the passage, the white ribbon on the big apple tree means _____. [ ]

A. pleasure

B. forgiveness

C. happiness

D. education

2. The word "suspense" underlined in the last paragraph can be replaced by _____. [ ]

A. pain

B. interest

C. worry

D. happiness

3. Why was Michael asked to watch for the apple tree? [ ]

A. The young man was afraid that he was refused by his family.

B. The young man's seat was far from the window.

C. The young man was afraid of seeing the white ribbons in the tree.

D. The young man was sure that his family would accept him.

4. Why were Michael's eyes filled with tears? [ ]

A. The young man couldn't live with his family.

B. He was moved by what he saw.

C. He was touched by the young man.

D. The young man was very sad.