题目

 Does Mary like documentaries?__________________.  A. Yes, she doesn't. B. No, she does. C. Yes, she does. 答案：C已知定义在R上的函数f（x）是奇函数且满足，f（-2）=-3，数列{an}满足a1=-1，且Sn=2an+n，（其中Sn为{an}的前n项和）．则f（a5）+f（a6）=（ ）A．-3B．-2C．3D．2