A well-trained teacher is not nervous, because she has the confident which comes of knowing that she is fully prepared for her work. She can help all her pupils, from the brightest to the slowest; and when she realizes, from the silence of her class when she asks a question, that they have not understood what she has explained, she is able to repeat her explanation again in different ways. Above all, she must never cause her pupils to lose confidence(信心). She must always speak to them kindly and when one of them turns red with shame at having answered a question after a long delay instead of easily, she must quickly make him or her feel at ease again. I was once sad to see a teacher being unkind to a girl who put up her hand and then answered a question with mistakes.

　　(46) A well-train teacher is never nervous because ___________.

　　A. she knows she has not got everything ready

　　B. she has enough confidence to do it ready

　　C. she never knows it is a shame

　　D. she'd like to be anything but a teacher

　　(47) The underline sentence "She can help all her pupils, from the brightest to the slowest" means that she can help____________.

　　A. neither the brightest pupils of hers nor the slowest ones

　　B. either the brightest pupils of hers or the slowest ones

　　C. not only the brightest pupils of hers but also the slowest ones

　　D. all her pupils with the white skins or dark skins

　　(48) When well-trained teacher sees the silence of her class, _______________.

　　A. she will teach them a good lesson

　　B. she would get angry

　　C. she will not explain it any more

　　D. she is sure to explain what she has explained over and over again

　　(49) When the pupils can't give her correct answers, ________________.

　　A. she will be kind and patient to them

　　B. she will let them turn red with shame

　　C. she will keep them standing for a long time

　　D. she will order them to think over the question

　　(50) Seeing a teacher was once unkind to a girl, ____________.

　　A. the writer got very unhappy

　　B. the writer put up his hand

　　C. the writer answered the question instead of the girl

　　D. the writer was asked to stand up