For most, but not all, HMO plans, youâll need a referral from your primary care physician before you can see any other health care professional (except in an emergency). If your plan requires a referral and you donât get one first, your insurance wonât cover the cost to see the specialist.
The strongest material would be boron fiber. That is not very practical because ot is expensive and brittle. The cost of carbon fiber is probably also too high to use for bridge strands. A drawn alloy steel wire is probably still the best choice, with tensile strengths of over 100,000 pounds per square inch being possible.
The electrical wires on high voltage pylons are generally aluminium, although it is a poorer conductor than copper it is much lighter so can be thinner to support it's own weight. Wires used on suspension bridge cables are steel. Also, wires used as filaments in light bulbs are made from tungsten.