下列计算:①0﹣(﹣5)=0+(﹣5)=﹣5;②5﹣3×4=5﹣12=﹣7;③4÷3×(﹣13)=4÷(﹣1)=﹣4;④﹣12﹣2×(﹣1)2=1+2=3.其中错误的有( )
如图,AB是圆O的直径,弦CD⊥AB于点E,点P在圆O上且∠1=∠C.
(1)求证:CB∥PD;
(2)若BC=3,BE=2,求CD的长.
This is ____(my/mine)pen. That pen is ____(my/mine).