The top leaders of the two countries are holding talks in a friendly________.
A:atmosphere
B:state
C:situation
D:phenomenon
下面是三种生物的形态结构示意图,相关叙述错误的是( )
下列命题中,真命题是( )
如图,在矩形纸片ABCD中,已知AD=8,折叠纸片,使AB边与对角线AC重合,点B落在点F处,折痕为AE,且EF=3,则AB的长为( )