Credit cards are read using something called a card reader or a read head.

读取信用卡要用到一种叫读卡器或者读头的东西。

The Tang Emperor smiled as his head monk read to a small group of people.

大唐皇帝微笑着听高僧给一小群人读经。

All, at any given time only one read head should be present in a card slot.

任何时候，卡槽里只能有一个读头。

There was also a separate read head could detect the polarity non-destructively.

还有一个单独的读头可以非破坏性地检测极性。

The storage principle is the same, the surface of a disk is magnetic, allowing write and read heads to store and retrieve 1's and 0's.

存储原理是一样的，磁盘的表面是磁性的，允许写入和读取磁头存储和检索 1 和 0。