Suppossedly, it is a possible for a moment to occur (with the same magnitude) at any point along a beam. But this not mean that there is any corresponding force. (So if you choose a point to calculate the moment about, the concentrated moment is a constant). So, how exactly does this work?
Since your question makes no sense otherwise I am going to assume you mean zero shear force and that you understand beam loadings for shear and moment. The attachment shows a two span continuous beam with a uniform loading. Beneath are shear and moment diagrams. Notice that at certain sections the shear force is zero - this corresponds to local maxima in the bending moment. Depending upon the sign convention you use, you may be familiar with such diagrams the other way up.