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问题 选择题

小明在一次劳动中不小心手被划破了皮，开始有血慢慢渗出，不过很快自然就止血了．请问这是血液中哪种成分的作用（　　）

A．血浆

B．红细胞

C．白细胞

D．血小板

答案

血液由血浆和血细胞组成，血细胞包括红细胞、白细胞和血小板．血浆的功能是运载血细胞，运输养料和废物；红细胞的功能是运输氧，白细胞的功能是吞噬病菌，防御和保护，血小板的功能是加速凝血和止血．综上所述A、B、C、选项错误，只有D选项正确．

故选：D

听力题

单词拼写（10分，每词一分）根据首字母提示或句意拼写出完整的单词。

1. We all_______(钦佩)her for the way she saved the child from the fire.

2. Just to satisfy my_______(好奇心),how much did you pay for your house?

3. The ______(氛围)over dinner was warm and friendly.

4. You are only ______(稍稍)underweight for your height.

5. Several _______(十年)have passed since I graduated from the college.

6. Let’s get something to eat ; I’m s________.

7. Medals were a_______ to the best speakers on the debating team.

8. It’s said Yoga is of great b_______ to human health.

9. I’ll come tomorrow if weather p________.

10.The s_______ of the disease frightened the villagers.
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填空题

长方体的棱长总和=______，正方体的棱长总和=______．
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