A:②③
B:①③
C:①④
D:②④
皮肤能防止病菌侵入人体,这种免疫属( )
(____) He is making a birthday card.
(____) He's in his room.
(____) When is Jack's birthday?
(____) Where's Jim?
(____) Who is he making it for?
(____) What is he doing?
(____) Tomorrow.
(____) He is making it for his friend,Jack.