男性，69岁，反复咳嗽、咳痰30年，气短8年；1周前开始发热，咳嗽、咳脓性痰，呼吸困
题型：单项选择题
问题：
男性，69岁，反复咳嗽、咳痰30年，气短8年；1周前开始发热，咳嗽、咳脓性痰，呼吸困难，来院诊治。血气分析； pH7.40，PaO250mmHg，PaCO270mmHg， BE14.5mmol/L。
该患者采用哪种浓度的氧疗较为合适
A．10%～20%
B．25%～30%
C．35%～40%
D．45%～50%
E．55%～60%
题型：单项选择题
| 选择恰当的一项，完成对话。 |
| 1. Tom: Jim: Yes. I have three erasers. |
[ ] |
| A. How many erasers are there? B. May I have an eraser? C. Do you have any erasers? |
2.  |
[ ] |
| A. Yes, it is. B. Sure. C. My pleasure. |
| 3. —How much are the donuts? —Two yuan. — |  |
[ ] |
| A. There are four donuts. B. I'll take five donuts. C. I'll take four, please. |
| 4. —How much is this? —Twenty yuan. —Oh ! |  |
[ ] |
| A. Thanks. B. I don't like it. C. That's expensive. |
