A:To say "thank you" to Betty.
B:To say "happy birthday" to Betty.
C:To say "happy New Year" to Betty.
等腰三角形的两条边长分别为3cm,7cm,则等腰三角形的周长为( )cm
下列物质中,不属于脂质的是( )
如图,AC=BD,AB=DC.求证:∠B=∠C.