A:what
B:who
C:whom
D:whose
Today is Monday. It is sunny today. There is a sports meeting in our school. There are many students and players on the playground. Some basketball players are playing over there, and their classmates are watching. Some girls are running. There is a big tree on the playground. Some boys are jumping under the tree.
细胞是生命活动的基本单位,下列有关细胞结构和功能的叙述,不正确的是( )
已知圆C的圆心在直线l1:x﹣y﹣1=0上,与直线l2:4x+3y+14=0相切,且截得直线l3:3x+4y+10=0所得弦长为6,求圆C的方程.