下列用于鉴定蛋白质的试剂及其颜色反应是( )
A:苏丹Ⅲ染液,橘黄色
B:斐林试剂,砖红色
C:碘液,蓝色
D:双缩脲试剂,紫色
“看万山红遍,层林尽染,漫江碧透,百舸争流,鹰击长空,鱼翔浅底,万类霜天竟自由”描述了( )
– Mum, I've been studying English since 8 o'clock. _____ I go out and play with Tom for a while?– No, I'm afraid not. Besides, it's raining outside now.
已知等差数列{an}满足a3=7,a5+a7=26,数列{an}的前n项和Sn.
(Ⅰ)求an及Sn;
(Ⅱ)令bn=1an2-1(n∈N*),求数列{bn}的前n项和Tn.
回答下列问题: