题目

 Rather than            on a crowded bus, he always prefers           a bicycle. A. ride; ride        B. riding; ride      C. ride; to ride    D. to ride; riding 答案：C已知等比数列{an}为递增数列．若a1＞0，且2（an+an+2）=5an+1，则数列{an}的公比q=______．