be attached to后面是接doing，因为to为介词后接名词或动名词，be attached to中文意思是喜爱；附属于

When we talk about a point we are referring to a piece of stone that's worked to a sharp point, in this case probably to be attached to a spear.当我们说到矛头的时候，我们所指的都是一块被加工成尖头的石块，在这种情况下，这一石块很可能是要接在矛上的。