[…] If a teacher is normally noisy and energetic as a teacher, he or she should spend a class behaving more calmly. This is so because each time teachers break their own behavior patterns, they send a ripple through the class. That ripple is a mixture of surprise and curiosity and it is a perfect starting point for student involvement. The need for surprise and curiosity within a fifty-minute lesson is also overwhelming. This can be seen most clearly with children at primary and secondary levels, but even adults need a varied diet to keep them stimulated. However, variety is not the same as anarchy, since students need a certain amount of predictability for the sake of stability. (Adapted from: HARMER, Jeremy. How to be a good teacher. England: Longman, 1998, p. 5.) Ainda no trecho acima o uso do conectivo since indica: