A:universal
B:logical
C:artificial
D:Regular
— Mabel, did you catch a cold again?
—Yes. I didn't realize the importance of doing enough exercise.
将曲线x+y2=1绕原点逆时针旋转45°后,得到的曲线C方程为____ .
下列各句中,没有语病、句意明确的一项是( )