问题
单项选择题
用轮廓算术平均偏差Ra来评定表面粗糙度，勋的单位是（）。
A．厘米
B．毫米
C．微米
D．纳米
答案
参考答案：C
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用轮廓算术平均偏差Ra来评定表面粗糙度，勋的单位是（）。
A．厘米
B．毫米
C．微米
D．纳米
参考答案：C
| 阅读短文，选择正确答案。 |
 | Here is a map of China. Do you know what country is east of China? Yes, it's the U. S. Australia is south and east of China. Beijing is the capital city of China. We speak Chinese in China. |
| 1. What country is this? |
[ ] |
| A. Australia. B. China. C. Beijing. |
| 2. Where is Australia? |
[ ] |
| A. It's south and east of China. B. It's east of China. C. It's north of China. |
| 3. What's the capital city of China? |
[ ] |
| A. It's Washington. B. It's London. C. It's Beijing. |
| 4. What do we speak in China? |
[ ] |
| A. Chinese. B. French (法语). C. English. |
| 5. Is this a map of China? |
[ ] |
| A. Yes, it is. B. No, it isn't. C. No, it's a map of China. |