题目

 Mr Li is one of teachers in our school. We all like him very much.           A. humorous                   B. more humorous           C. the most humorous           D. much more humorous 答案：C2．已知$\frac{π}{2}$＜α＜π，-π＜β＜0，tanα=-$\frac{1}{3}$，tanβ=-$\frac{1}{7}$，求2α+β．