磁铁的南北极形成了一个偶极子。

The north and south poles of a magnet form a ___dipole.

我们安装了一个简单的偶极天线来接收无线电信号。

We installed a simple ___dipole to pick up radio signals.

水分子是一个典型的电偶极子，具有正负电荷分离的特性。

The water molecule acts as an electric ___dipole with separated positive and negative charges.