—Do you think I could borrow your bicycle?

—        

A．How come?

B．Take your time.

C．Yes,go on.

D．Yes,help yourself.

支原体肺炎可用（）

A．头孢菌素 

B．头孢他定 

C．头孢拉定 

D．头孢吡肟 

E．头孢呋辛