“一带一路”即“新丝绸之路经济带”和“21世纪海上丝绸之路”,是******提出的战略构想,旨在借用古代“丝绸之路”的符号,沟通历史与未来,连接中国与世界.古代丝绸之路经过的地方有( )
A:南非
B:河西走廊
C:洛阳
D:辽东
唐朝长安城内繁华的商业区叫做( )
I had a________experience yesterday.The brake of my electrical bike failed and I was very________then.
如图,在△ABC中,∠C=90°,∠B=30°.
(1)作∠A的平分线AD,交BC于点D(用尺规作图,不写作法,但保留作图痕迹,然后用墨水笔加黑);
(2)计算S△DAC:S△ABC的值.
已知:4x2+kx﹣5=(x+1)•A(A为多项式),则A=____