下列说法正确的是（　　）

A．平面内，两条互相垂直的直线构成数轴

B．坐标原点不属于任何象限

C．x轴上的点必是纵坐标为0，横坐标不为0

D．坐标为（3，4）与（4，3）表示同一个点

Scott was very nervous at the beginning, but finally he _____ his courage to speak it out, and the teacher accepted his apology and forgave him.

A．made up

B．brought up

C．worked up

D．lived up