问题 单项选择题 A1/A2型题

下列关于X线成像的基本原理中,不正确的是()。

A.X线具有穿透性

B.人体组织之间有密度差异

C.人体组织之间有厚度的差异

D.X线具有感光效应

E.X线具有电离效应

答案

参考答案:E

解析:X线成像的基本原理主要包括两个方面:一方面是基于X线的穿透性、荧光效应和感光效应等特性;另一方面是基于人体组织之间有密度和厚度的差异,这种差异在X线穿透人体时被吸收的程度不同,产生了黑白对比不同的影像。

单项选择题
阅读理解

Do you love American country music? If you do, come to Nashville. It’s the home of American country music.

Nashville is the capital city of the state of Tennessee. Here you don’t have to go to the big auditoriums(音乐厅) to enjoy the country music. In the open air restaurants or on the streets, you can always hear the beautiful and sweet sounding folk music. All the singers are young and they play their guitars while they sing. The songs they sing are so touching(动人) that, if you listen attentively, you can feel they are singing with their souls rather than with their voices.

Shops selling music records and tapes can be found everywhere in Nashville. Many records are made by famous singers and they are sent to many countries all over the world.

The folk songs most of the singers sing come form the rural areas in the southern United States. The songs often describe those days to situations and the feeling of the country people. They often sing in praises of heroism(英雄) and true love.

1. From the passage we know Nashville is ________.

A. a village       B. a big city   C. a small town        D. a capital city

2. To enjoy the country music, you can go to ________.

A. the big auditoriums   B. the open air restaurants    C. the streets  D. All of the above

3. According to the passage which of the following statements is not true?

A. Shops that sell music records and tapes can be found everywhere in Nashville.

B. The folk songs can impress you deeply

C. Not all records are made by famous singers

D. The folk songs only sing in praises of heroism and true love.

4. The passage is mainly about ________.

A. Nashville  B. American young people   C. pop singers   D. the country music