题目

Chip was in first grade when I arrived at his school as a counselor(辅导员). It was shocking to me that he was described as an angry, uncontrollable and evil(惹人厌的) boy. How could such a little boy, after being in school only one year, be considered “evil”？ Over the next several months, I came to know Chip well enough to see that he was neither evil nor uncontrollable.But, one day, Chip threw a chair at his teacher and was sent to my office. I asked him what made him do this. He replied that his teacher hated him. He felt there was no way to ever get her to like him. I asked hi在等差数列中，若，则 [　　] A．45B．75C．180D．300