磁铁的方向性决定了它的两极指向。

The ___directionality of a magnet determines its pole orientation.

这款扬声器的指向性设计让声音只向特定区域传播。

The speaker's ___directionality ensures sound only travels to specific areas.

风向标清楚地显示了气流的流向。

The weather vane clearly shows the ___directionality of the air flow.