努力学习也是孝敬父母的表现。 [ ]
√
已知动圆P与定圆C：（x+2）2+y2=1相外切，又与定直线L：x=1相切，求动圆的圆心P的轨迹方程．
Every man has his faults. We should, therefore, learn to be ______ of others.
A．ignorant
B．responsible
C．reliable
D．tolerant
