如图,半圆O的直径在梯形ABCD的底边AB上,且与其余三边BC,CD,DA相切,若AB=10,BC=4,则AD的长( )
“生活就像一面镜子,你笑,它也笑;你哭,它也哭。”这句话说明( )
—They ______ really hard. There is no success without effort.