Here's a roundup of news trending across the nation and world today.

What to know now:

 1. Not ransom: In a press conference Thursday, President Barack Obama strongly denied that a $400 million cash payment made to Iran in January was ransom in exchange for the release of four Americans detained in that country. "This wasn't some nefarious deal," Obama said during a press conference at the Pentagon.  The payment was a part of restitution the U.S. is making in a 40-year dispute over a military equipment deal that took place before the Islamic revolution in 1979, the president said.

2. Olympics are here: Get ready for some serious sports action as the 2016 Summer Olympic Games get under way from Rio de Janeiro. The opening ceremonies are set for 8 p.m. ET (with a preview beginning at 7:30 p.m. ET). Swimmer Michael Phelps will be carrying the flag for the United States in the Parade of Nations.

3. MH370 pilot: Officials in Malaysia have, for the first time, acknowledged that a pilot on Malaysia Airlines Flight  370 used a flight simulator kept in his home to plot a course that took a plane to the southern Indian Ocean – the place authorities believe the flight disappeared. Capt. Zaharie Ahmad Shah used a flight simulator to plot the course, officials say, but they also noted that there were thousands of courses plotted on the simulator and that they have no evidence that proves Zaharie deliberately flew the plane into the Indian Ocean. The flight  was on route from Kuala Lumpur to Beijing when it disappeared with 239  people on board.

4. Father arrested: A Georgia father was arrested Thursday after his twin 15-month-old daughters died after being left in a hot car. Asa North was charged with two counts of involuntary manslaughter and two counts of reckless conduct after the children were pronounced dead at a Carrollton, Ga., hospital. Police say that when they arrived, North had the girls in the pool of the apartment complex where  they lived, trying to cool them off.

5. Young whites aren't Hillary fans: In a new poll, young, white Americans say they believe that Hillary Clinton lied about her email account and intentionally broke the law when she set up a private email server in her New York home. In a new GenFoward poll of Americans 18-30, found that both Clinton and Donald Trump have high negative numbers with young people. In the survey, people of color were more likely to give Clinton the benefit of the doubt in the email scandal.

And one more

Facebook says it intends to reduce the  number of "clickbait" headlines you will see in the site's news feed. The headlines  leave out important information in order to get the reader to "click" onto the story to find out what it is about. This change comes a little more than an month after Facebook announced it would prioritize posts from friends and family over those from publishers or companies.

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