A:x1>x2
B:|x1|<|x2|
C:x1>|x2|
D:x12>x22
Our school library has floors, and the reading room is on the floor.
流行性感冒的传播途径主要是( )
已知曲线C上的动点M(x,y)和向量a=(x+2,y),b=(x-2,y)满足|a|+|b|=6,则曲线C的离心率是( )
填上合适的单位