将松树和桃树这两种植物相比较，最主要的区别在于（　　）

A．松树的种子外面有果皮包被着

B．松树没有果实，种子裸露着

C．松树的松球果包被着果皮

D．松树的松球果有鳞片

-____________________

-They're under the chair.[ ]

A. Where is your baseball?

B. Where are your baseball?

C. Where are your keys?

D. Where is your keys?