把一条线段向一端延长100米，就得到一条射线．______．

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问题解答题

答案

把一条线段向一端延长100米，得到的还是一条线段；

故答案为：×．

补全对话，情景问答

Ⅰ	Ⅱ
( )1. Where shall we meet? ( )2. Do you skate much? ( )3. I have a toothache. ( )4. Who is your favorite player? ( )5. Would you mind helping me ?	A. Yes, I do. B. At the school gate. C. Yao Ming. D. Of course not. E. I' m sorry to hear that.

单项选择题

某慢性肺源性心脏病病人，70岁，缺氧和二氧化碳潴留同时并存，发绀，宜选用的氧浓度是( )。

A．21%
B．29%
C．33%
D．37%
E．41%