If there is one person who has left a deep impression on me, it's my teacher Mrs. Pathak who was my class teacher for three years. In my childhood, how I wished I had a mother or a sister like her. One moment she could be tough   and strict, another moment caring and compassionate  . She always encouraged us to tell the truth. For instance, if one had not done the homework, he need not lie. She allowed us to make mistakes, saying we couldn't be perfect all the time, but we should try. Another thing she taught me early on was punctuality. She set a good example with her own behaviour. She was always on time, so we students tried our best to be on time. She surprised us with her sense of humour. Her classroom teaching was always humorous. After class, she talked to us and told us jokes. We really felt free to ask questions and Mrs. Pathak would give the answers. If she did not know -- there had been some occasions   -- she would say _ We all then tried to find out the answers. Whoever came up with the answer was appreciated and given the due credit  . Now I sometimes wonder whether Mrs. Pathak was pretending just to encourage us to explore and find answers by ourselves. According to the passage, which of the following is NOT suitable for describing Mrs. Pathak?
Tough. Humorous. Compassionate. Careful.