阅读以下1-5段材料，然后从A-f中选出各段的主题。有一项为多余选项。
A. A good teacher acts in class
B. Acting: repetition of fixed words and movements
C. Teaching: a student-centered creative process
D. Similarities between teaching and acting
E. ( = AB) Differences between teaching and acting
F. ( = AC) A good teacher, not necessarily a good actor
1 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 audience; you must be a clear speaker, with a good, strong, pleasing voice
which is fully under your control; and you must be a- ble to act what you are teaching, In order to make
its meaning clear.
2 Watch a good teacher, and you will see that he does not sit unmoved before his class: he stands
the whole time he is teaching; he walks about, using his arms, his hands and fingers to help him in his
explanations, and his face to express feeling. Listen to him, and you will hear the loudness, the quality and
the musical note if his voice always changing according to what he is talking a- bout.
3 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 well in the stage, for there are very important differences 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 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.
4 A good teacher works in quite a different way. His audience takes an active part in his play: they
ask questions, they obey orders, and if they don't understand something, they say so, the teacher therefore
has to suit his act to the needs of his audience. He cannot learn his part by heart, but must invent it as he
goes along.
5 As a good teacher presently, you must take your au- dience as your friends, take care of them, help
them and give them enough freedom and space. I have known many teachers who were fine actors in class
but were unable to take part in a stage play be- cause their brains wouldn't keep discipline: they could not
keep strictly to what another had written.