Article continues below advertisementPresident Donald Trump sparked fresh chatter about his health after a tense moment at a major public event, where he appeared to blank on the name of a foreign leader he was meant to formally introduce.While speaking at the National Prayer Breakfast on Thursday, the 79-year-old president praised the President of the Democratic Republic of the Congo, Felix Tshisekedi, describing him as a "very, very brave, wonderful man." However, when it came time to introduce him by name, Trump faltered.Article continues below advertisement"The president of the Congo...