直线y=2x+1的参数方程是 ( )
A:x=t2y=2t2+1
B:x=2t-1y=4t+1
C:x=t-1y=2t-1
D:x=cosθy=2sinθ+1
____+45=____+55,这里运用了加法____,用字母表示是____.
855°转化为弧度数为____