对于向量a,b,c,有().。 ()-|||-A )若 overrightarrow (a)cdot overrightarrow (b)=0, 则a,b中至少有一个零向量;-|||-B) (overrightarrow (a)+overrightarrow (b))cdot overrightarrow (c)=(overrightarrow (b)cdot overrightarrow (c))+(overrightarrow (a)cdot overrightarrow (c)) ;-|||-C) (overrightarrow (a)cdot overrightarrow (b))cdot overrightarrow (c)=overrightarrow (a)cdot (overrightarrow (b)cdot overrightarrow (c));-|||-D), (overrightarrow (a)cdot overrightarrow (b))(overrightarrow (a)cdot overrightarrow (b))=0.