下列航海家中发现了美洲新大陆的是( )
A:哥伦布
B:迪亚士
C:麦哲伦
D:达.伽马
This morning Ella called the manager to say that she was unable to work________a bad cold.
①附中高一年级聪明的学生;
②直角坐标系中横、纵坐标相等的点;
③不小于3的正整数;
④3的近似值;
考察以上能组成一个集合的是____