按要求画出下列图形．

①把长方形绕点A逆时针旋转90度．

②把三角形绕点B顺指针旋转90度．

③图形3补全，使它成为轴对称图形．

要使分式有意义，x的取值范围满足【   】

Red Star Restaurant
The biggest and busiest restaurant in Jinan is seeking 20 waiters who have relevant (相关的) experiences in high-grade restaurants. About ¥800—1,500 per month.
Red Star Restaurant is located at 66 on Park Street.
Our phone number is 0531-8278-4560.
3 People wanted
Need 3 people who would like to work 4 evenings per week showing films. Earn $300 per week possibly. Call 469-867-6042.
Baby-sitter wanted
For a year. 3 days a week. Some flexible (灵活的) hours required.
Knowledge: above senior middle school.
Call 0431-478-9971.

分别完全燃烧1molC₂H₆、C₂H₄、C₂H₂、C₂H₆O，需要氧气最多的是（   ）

原子弹和核电站的根本区别是（）