冷水泵流量不足是由于水泵叶轮堵塞或管道过滤器堵塞。
参考答案:对
在数列{an}中,a1=1,a2=2,且an+1=(1+q)an-qan-1(n≥2,q≠0),
(Ⅰ)设bn=an+1-an(n∈N*),证明{bn}是等比数列;
(Ⅱ)求数列{an}的通项公式;
(Ⅲ)若a3是a6与a9的等差中项,求q的值,并证明:对任意的n∈N*,an是an+3与an+6的等差中项。
— ______ clean room!
— Of course. It every day. [ ]
A .What; must sweep
B.How; is swept
C.What a; must sweep
D.What a; is swept