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问题 填空题

在夏天打雷时，雷声和闪电同时发生，但我们总是先看见闪电，后听见雷声这是因为______．

答案

闪电和雷声是同时发生的，根据传播速度表可知，声音的传播速度是340米/秒，光的传播速度是3×108米/秒，那么我们先看到闪电，后听到雷声的原因是空气中光的传播速度大于声音的传播速度．

故答案为：在空气中光的传播速度大于声音的传播速度．

改错题

此题要求改正所给文中的错误。对标有题号的每一行做出判断：如无错误，在该行右边的橫线上划一个勾（√）；如有错误（每行只有一个错误），则按下列情况改正。此行多一个词：把多余的词用斜线（／）划掉，在该行右边的橫线上写出该词，并也用橫线划掉。此行缺一个词：在缺词处加一个漏字符号（∧），在该行的右橫线上写出该词。此行错一个词：在错的词下划一橫线，在该行右边橫线上写出改正后的词。

注意：原行没有错的不要改。

They day before the speech contest（比赛） English teacher   小题1:____________

　　talked to me . She said that she and my schoolmate all       小题2:____________

　　wished me success , but it didn't matter that I would         小题3:____________

　　win or not . When I was on the stage the next day , I felt so   小题4:___________

　　nervous as I shook like a leaf . There were so many people    小题5:___________

　　present! Suddenly , I caught a sight of my English teacher in   小题6:___________

　　the crowd . She was smiling but nodding at me. I remembered  小题7:__________

　　her words and calm down . I did a good job and won the first    小题8:__________

　　prize . Now my picture and the prize is hanging in the library.   小题9:___________

　　Whenever I see them I will seldom think of my English teacher. 小题10:__________
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单项选择题

下列属于中脑的结构是( )

A．嗅球

B．外侧膝状体

C．面神经丘

D．橄榄

E．大脑脚
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