内容摘要：A selection of news photographs from around the world.

A selection of news photographs from around the world.

Meanwhile, Ms Caldwell's family have launched a class action lawsuit against manufacturers and distributors of nitrous oxide, hoping to remove the product from retail sales across the US for good."The people who administer nitrous oxide in a dentist office now have to go through hours and hours of training, she said. "It just is crazy to me that the drug can be purchased in a smoke shop to anyone who goes in."

"Unfortunately, it's become very obvious that the manufacturers and the owners of the smoke shops are not going to do the moral thing and take this off the shelves themselves," Ms Dial said.A college in Beijing has found itself at the centre of public fury after it allegedly asked a student to prove she was on her period to qualify for sick leave.A viral video, filmed inside what appears to be a clinic and posted to social media this month, shows a young woman asking an older woman: "Does every menstruating girl have to take off their trousers and show you before they can get a sick note?"

"Basically yes," the older woman replies. "This is a school rule."Local media identified the video's location as a clinic at the Gengdan Institute university college, which later said in a statement that its staff had "followed protocol". But social media users have decried the encounter as a serious invasion of privacy.

Neither the student nor Gengdan Institute immediately responded to BBC News' requests for comment.

Both the student's video and the school's statement appear to have been taken down, though screenshots and snippets have been recirculated online, including by state media.They are seeking at least $50m (£38m) in damages and a jury trial.

The Los Angeles County Sheriff's Department then opened its investigation, which the 85-year-old singer said at the time he welcomed "because exposure to the truth is a powerful thing".Mr Robinson was Motown's first hitmaker, writing number one records like Mary Wells' My Guy and The Temptations' My Girl.

He was both a talent scout for the record label and one of its most prominent recording artists in his own right, known for songs like Tracks of My Tears, Shop Around and Tears of a Clown.He has spots in both the Rock & Roll Hall of Fame and the Songwriters Hall of Fame, and claims to have credits on more than 4,000 songs.