用方框中所给单词的适当形式完成短文。
corner, be, watch, play, fast, but, over, between, after, activity
俗话说“大树底下好乘凉”、“千里之堤溃于蚁穴”.这都体现了( )
如图,在正方形ABCD中,E、F分别是边AD、CD上的点,AE=ED,DF=14DC,求证:△ABE∽△DEF.