A. ill B. school C. doctor D. teacher E. cold
— , but are you sure it's not too much trouble?
如图,正△ABC的边长为4,点P为BC边上的任意一点(不与点B、C重合),且∠APD=60°,PD交AB于点D.设BP=x,BD=y,则y关于x的函数图象大致是( )
下列关于生物多样性的叙述,正确的是( )