His erasers are in his ____ (mother) bag.
“野火烧不尽,春风吹又生”,说明生物所具有的特征是( )
坚持党的基本路线不动摇,必须处理好改革,发展与稳定的关系,其中稳定是( )
构造如图1所示的图形,在⊙O中,AB是直径,点C在⊙O上,所以∠ACB=90°,作CD⊥AB于D.设∠BAC=α,则sinα= BCAB=13 ,可设BC=x,则AB=3x,….