— See ________ light in the sky?

— Yes，it’s moving fast．It must be ________ plane．

A．a；the

B．the；不填

C．the；a

D．不填；a

－See ________ light in the sky?

－Yes．it's moving fast．It must be ________ plane．

A．a; the

B．the; 不填

C．the; a

D．不填; a