A competitive swimmer in Syria, Yusra Mardini never let go of her Olympic dream, even when civil war made it too difficult to train in her country. In 2016, she was allowed to compete in the Rio Olympics as part of a special team for refugees. This was only months after making a daring crossing of the Mediterranean Sea in a sinking boat that she helped tow to shore. Dozens of lives were saved on the voyage. Still training, Mardini also acts as a spokesperson...