People often feel shy to speak in public if______.

A．If a speaker worries about his appearance, he can find some ways to turn people's attention away from his look.
B．During a speech, people generally will not spend the whole time on the speaker's appearance.
C．Proper clothing and accessories can also improve one's social attractiveness.
D．If one keeps his hair tidy and body clean, then he possesses the natural beauty.

A．It has created a sensation among artificial intelligence researchers but will soon die out.
B．It's a breakthrough in duplicating human thought processes.
C．It's more like a peculiar game rather than a real scientific effort.
D．It may prove to be in the right direction though nobody is sure of its future prospects.