Why are there limitations to changing field properties?

为什么会有更改的字段属性的限制？

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After selecting a field type, you can set other field properties.

选取栏位型别之后，就可以设定其他栏位属性。

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Individual fields can be hidden or restricted by modifying the field properties (see figure 4).

可以通过修改字段属性来隐藏或限制单个字段(参见图4)。

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Twelve houses in Astley still have water in their gardens from a flooded field at the back of their properties.

BBC: Astley villagers' gardens still flooded after 10 weeks

Its optical properties might be modified by merely applying a magnetic field.

FORBES: Magazine Article

These discoveries have given birth to a field of endeavour that is known as spintronics, because the magnetic properties of a material depend on a quantum-mechanical property of electrons called spin.

ECONOMIST: Spintronics