We have been in the school ______ three years ago and Mrs. Lee Has taught us English_______ three years.
树立健全的环境意识,必须( )①掌握环境科学知识 ②树立正确的环境价值观 ③实现人与自然和谐相处 ④理解、接受并遵守环境伦理原则和相关的行为规范
(Ⅰ)求圆C的直角坐标方程与α的取值范围;
(Ⅱ)若点P的坐标为(﹣1,0),求 1|PA| + 1|PB| 取值范围.