We are busy in preparing for the performance in order not to________in front of our classmates.
A:lose hope
B:lose face
C:lose confidence
D:lose heart
盒中装有形状,大小完全相同的5个球,其中红色球3个,黄色球2个,若从中随机取出2个球,已知其中一个为红色,则另一个为黄色的概率为( )