common node elements的意思|示意

Simplicity: the program can use these node tests to select a group of elements based on their common group head element or type definition rather than enumerate all concrete element names one by one.

简单性：程序可以使用这些节点测试，选择基于共同组head元素或类型定义的一组元素，而不是逐一列举所有具体的元素名。

The elements and the common eight-node plane elements have the same element character and accuracy.

此种单元和平面八结点单元具有相同的单元特征及精度。