题目

-----I should have gone to the wonderful concert with you yesterday. -----_______. If only we would have another such chance. A. Yes, you should                     B. What a shame！       C. That’s all right                      D. Take it easy 答案：B 解析: 略9．已知f（x）=$\frac{{2}^{1+x}+{2}^{1-x}+arcsinx}{{2}^{x}+{2}^{-x}}$的最大值和最小值分别是M和m，则M+m=4．