We can obviously notice that over a period of no practice, what has been learned tends to be forgotten from________________________.

A．Because the smoking actors in the movies have good-looking bodies.
B．Because the movies show that smoking is necessary for social activities.
C．Because the movies convey that smoking enhances the image of a man.
D．Because the actors tell the audience that smoking causes no harm.

A．A camera can be carried about with him, but his mind can’t.
B．A camera can record what he sees and his mind can’t.
C．He may have a mind, but he doesn’t necessarily have a camera.
D．His mind can record what he feels and tastes, but a camera can’t.