与频谱多普勒相比，彩色多普勒血流显像的优点是（） A.显示血流_爱下问搜题

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问题单项选择题 A1/A2型题

与频谱多普勒相比，彩色多普勒血流显像的优点是（）

A.显示血流速度的范围

B.显示高速血流时无混叠

C.计算流速更准确

D.可显示血流空间分布情况

E.定量计算血流容积

答案

参考答案：D

解析：彩色多普勒血流显像，又称二维多普勒，它把所得的血流信息经相位检测、自相关处理、彩色灰阶编码，把平均血流速度资料以彩色显示，并将其组合，叠加显示在B型灰阶图像上。它能较直观地显示血流空间分布情况，对血流的性质和流速在心脏、血管内的分布较脉冲多普勒更快、更直观地显示。对左向右分流血流以及瓣口反流血流的显示有独到的优越性。但对血流的定量不如脉冲波和连续波多普勒。

单项选择题

炫耀性物品是用以显示人们的身份和社会地位的物品。由于这种物品只有在高价位时才能起到炫耀的作用，所以其需求量与价格成（）关系。

A.反方向变化

B.同方向变化

C.无变化

D.无法确定

完形填空

My mother only had one eye. And because of this, I never wished her to show up in my school, being afraid that my classmates would     I had an ugly mother.
One day during elementary school, I was terribly ill. My mother came.
“Your mom only has one eye?!” asked some of my classmates. I was so     .
I wished my mother would just     from this world. “If you make me teased(嘲笑)，why don’t you just die?” I shouted at her, taking no notice of the sad look on her face. My mother just handed me some medicine and left without saying     .
At that time, I felt     to say what I always wanted to say, and I didn’t think I had hurt her feelings very much. That night I saw my mom     in her room, so quietly, as if she was afraid that she might     me. Even so, I hated her tears from one eye. I made a     : I must study hard and leave my mother.
Years later my dream came true. I was quite successful and lived     . I never thought of going back to see my “ugly” mother     one day I got a letter, which said, “My son… I’m sorry I only have one eye. When you were little, you got into a(n)     and lost your eye. As a mom, I couldn’t     watching you live with only one eye.       I gave you mine. I was never     with you and I never regretted(后悔) what I did because I     you…”
I cried out aloud. Only then did I realize how beautiful my mother was!

B．embarrassed

B．appointment