但是，关联的多重性经常不是任意的，而依赖于属性值，这不能用图形建模语言，例如UM l类模型来表示。

However, the multiplicity of associations often is not arbitrary, but depends on attribute values, which cannot be expressed with graphical modeling languages such as UML class models.

youdao

在 UML 中，关联与模型中的两个或多个类有关，关联由带数字的单箭头表示，数字意味着该关联的多重性。

In UML, an association relates two or more classes in a model and is indicated by an arrow on one end along with a number implying the multiplicity of that association.

youdao

因为类的多重继承有危险性。

Because multiple inheritance of classes is dangerous.

youdao