superstition

她有个迷信的想法，认为蓝色袜子会带来好运。

She has a ___superstition that blue socks bring good luck.

有些人认为黑猫会带来厄运，这不过是一种迷信。

Some people believe black cats bring bad luck, which is just a ___superstition.

她认为打破镜子会带来七年厄运，这纯粹是迷信。

She believes breaking a mirror brings seven years of bad luck, which is just ___superstition.