The Silk Road was ______ long that it passed through many countries.
A:quite
B:too
C:very
D:so
如图,矩形ABCD的长为8,宽为6,现将矩形沿对角线BD折叠,C点到达C′处,C′B交AD于E.
已知α为锐角,cos(α+π4)=55.
求tan(α+π4)的值;
如图是绿色开花植物相关结构示意图,请据图回答下列问题: