Problem: Logical reason for their high debt. Several years back, Verizon bought GTE and some other rural telephone companies. The rural phone business is more expensive to operate because of the lower population density. It takes a lot more cable and additional equipment to serve homes spaced out widely than it does for the ultimate density--an apartment complex. This is why, if you look at your phone bill, there is a tax called the Universal Service Fund (USF), which was designed to supplement telco's expenses in delivering services to rural areas" Explain.