单选题
To be a good teacher, you need some of the gifts of a good actor: you must be able to hold the attention and interest of your students; you must be a【C1】______speaker, with a good, strong, pleasing voice which is fully under your control; and you must be able to【C2】______what you are teaching in order to make its meaning clear.【C3】______a good teacher and you will see that he does not sit still【C4】______his class: he stands the whole time when he is teaching; he walks about, using his【C5】______, hands and fingers to help him in his explanations, and his face to express feelings. Listen to him, and you will【C6】______the loudness, the quality and the musical note of his voice always changing according to what he is【C7】______about. The fact that a good teacher has some of the gifts of a good actor doesn' t mean that he will indeed be able to act【C8】______on the stage, for there are very important【C9】______between the teacher' s work and the actor's. The actor has to speak words which he has learnt by heart; he has to repeat exactly the【C10】______words each time he plays a certain part; 【C11】______ 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【C12】______on the stage. A good teacher【C13】______in quite a different way. His students take an active part in his【C14】______; they ask and answer questions; they obey orders; and if they don't understand something, they will say so. The teacher therefore has to suit his aet to the needs of his students. He cannot learn his part by heart, but must【C15】______it as he goes along.