The first two pictures are lucky bamboo, which is a Dracaena, more specifically Dracaena sanderiana. The third I can't quite upload. From what I'm seeing in the picture, it appears as though the Dracaena was grown in a pot filled with just water. If this is the case, they are probably dying because of excessive salt intake. The way to solve this problem, aside from getting new ones, is to cut off the larger part of the stem that looks dead, and plant the tops in potting soil (make sure the pot has drainage holes). Salt buildup happens when tap water is not allowed to drain freely out the pot, and as the water becomes absorbed by the plant and evaporates, the salt remains. As this process continues, the salt in the water becomes more and more concentrated until the plant can't take it anymore.
הדמיון הוא יותר חשוב מאשר ידע