On today’s program we talk with two scientists who are developing ways to make a new, high-tech concrete. Why is that important?  They hope their new forms of concrete may someday help ensure that that our roads, bridges and buildings are more solidly built, last longer and provide a number of other benefits. Also… Scientists recently announced that the weather phenomenon known as El Nino is returning and could bring some extreme weather with it.  In fact, they say the El Nino might become the big weather story of the year. Public health officials are praising newly developed drugs that can eradicate the deadly disease Hepatitis C.  Now scientists are working to make those drugs cheaper so that more people around the world can afford the treatments. These stories and more are coming up for you on this edition of VOA's science, health and technology magazine, "Science World.