根据短文理解，选择正确答案。
MARS— The Red Planet
“MARS—The Red Planet!” is one of our Early Reader Space books. It has surprising facts and photos explaining all about Mars. Aiming mainly at kids aged 7—10, it's an interesting way for readers to find out more about the red planet.
The Weather
“The Weather” is one of our Early Earth books for boys and girls aged 13—15. This is a fun and fantastic way for readers to find out more about the weather on our earth. It offers information in a fun way—mixing facts, photos, and even has a web page with video clips explaining more about the information in the book.
Horses
Kids Book of Fun Facts & Amazing Pictures on Animals in Nature — A Perfect Horse Book for Kids Aged 5—8.
The book written by Kate describes the most noble animal on the planet for early readers. The book is packed with beautiful and clear pictures that help your child to understand the (fun) facts about this animal. It also includes anatomy(解剖) of horses.
中,圆
的方程为
,若直线
上至少存在一点,使得以该点为圆心,1为半径的圆与圆
的取值范围是（ ）