We’ll crack(破译) the genetic code and conquer cancer.As scientists learn more about the genetic code，many serious diseases，like cancer，will become less threatening.Using manufactured viruses，doctors will be able to replace cancer-causing damaged DNA with healthy genes，probably administered by a pill or injection.We’ll live longer.If the normal aging process is basically an invisible contest in our cells—a contest between damage to our DNA and our cells’ ability to repair that damage—then 21st-century strides(发展) in genetic medicine may let us control and even reverse the process.