题目

 _____, her suggestion is of greater value than yours.   A. All things considering         B. All things consideredC. All things were considered    D. With all things were considered 答案：B5．等比数列{an}的各项均为正数，且a1=3，a2是方程x2-5x-6=0的根．（1）求数列{an}的通项公式；（2）设cn=$\frac{{2}^{n-1}}{（{a}_{n}-1）（{a}_{n+1}-1）}$，求数列{cn}的前n项和．