How Does String Theory Marry Gravity and Quanta Mechanics?

A theory doesn't work when it can't predict the results of experiments. When you try to bring gravity into equono mechanics, you get lots of infinities. So how is string theory to solve that problem? Simple, says there are no points. At its smallest scale, the universe is not made of points, but strings. That's why string theory can bring together quanta, mechanics and gravity so nicely.