[单项选择]To be a good teacher, you need some of the gifts of a good actor: you must be able to hold the attention of your audience; you must be a clever speaker, with good, strong, pleasing voice which is fully under your control; and you must be able to act what you are teaching, in order to make its meaning clear.
The fact that a good teacher has some of the gifts of an actor doesn’t mean that he will indeed be able to act well on the stage, for there are very important differences between the teacher’s work and actor’s. The actor has to speak words which he has learnt by heart; he has to repeat exactly the same words each time he plays a certain part, even his movements and the ways in which he uses his voice are usually fixed beforehand. What he has to do is to make all these carefully learnt words and actions seem natural on the stage.
A good teacher works in quite a different way. His audience takes an active part in his play; they ask and answer questions, they obey orders, and
A. A teacher’s voice must be nicer than an actor.
B. A teacher cannot decide beforehand what exactly he is going to say in class.
C. A teacher must have better memory than an actor.
D. A teacher has to learn by heart what exactly he is going to say in class.