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问题 单项选择题

有关混响说法，不正确的是()

A．混响与超声波的散射特性有关

B．超声垂直照射到平整的界面上，超声波在探头和界面之间来回反射产生混响

C．混响的形态呈等距离多条回声，回声强度依深度递增

D．“气体反射”是混响的一种

E．适当侧动和加压探头可有助识别混响

答案

参考答案：A

选择题

人类活动影响最深刻最集中的地域类型是[ ]

A、海洋

B、乡村

C、城市

D、草原
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改错题

短文改错

文中共有10处语言错误，每句中最多有两处。错误涉及一个单词的增加、删除或修改。

增加：在缺词处加一个漏词符号（∧），并在其下面写出该加的词。

删除：把多余的词用斜线（＼）划掉。

修改：在错的词下划一个横线，并在该词下面写出修改后的词。  

注意：1. 每处错误及其修改均仅限一词；

            2.只允许修改10处，多者（从十一处起）不计分。

     Li Hua and I were neighboures and we went to same school. We always went to school together.

We were good friend and had a great deal to share with every day. However, one day, Li Hua copied

my homework, which made me such angry that I did not want to be friends with him any long. Then on

Monday morning I ran downstairs without realize it was raining, but there was no time to return home to

fetch an umbrella. It happens that Li Hua was just around the corner and be offered to share her umbrella with me. He made apology to me in a gently voce. I forgave him but gave him a hug.

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