Safety has a number of layers.

安全有若干层。

Your skin has a number of layers of different types of cells.

皮肤是由若干层不同类型的皮肤构成。

Here is our words: your skin has a number of layers of different types of cells.

我们是这么说的：皮肤是由若干层不同类型的皮肤构成。

In the meantime, the number of freedom degrees doesn't increase with the number of layers in the laminate as it does in the conventional case.

同时由于单元的自由度数不随层数的增加而增加，避免了常规三维单元在分析复合材料层板时自由度数随层数的增加而增加的弊端。

We're dealing with a number of layers, but they converge nicely on the realm of modeling domains and representing entities.

在我们正在处理许多层，但这些层很好地会聚到建模域和表示实体领域上。