If this alert is received, the pilots should put on masks which will provide them with oxygen while they rapidly descend the aircraft to an altitude where the occupants can breathe without assistance.

BBC: NEWS | Europe | Dangers of aircraft decompression

In a statement, Copenhagen police said a large group of protesters had organised themselves in a so-called "black bloc", in which they put on masks - an illegal action at a demonstration in Denmark.

BBC: Climate activists condemn Copenhagen police tactics

The objective was those scenes of mayhem and because you are talking about people who plan that, they come and they put on masks, it's difficult to get any shots of them and so on for the cameras and so they all got away, the ringleaders, last year.

BBC: News Online

We at She Negotiates see moving high potential and high-powered women into greater positions of greater responsibility and leadership as tantamount to the airline injunction to put your breathing mask over your own nose and mouth before you turn to put masks on your children.

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During the French Revolution, she was imprisoned, and later commissioned to create death masks of many of those put to death on the guillotine.

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In 2006 a warm summer has had people flocking to the beach, but that masks a diminishing number of visitors since the 1970s, which has put the town on the brink of a period of massive change.

BBC: NEWS | UK | England | Renaissance in Scarborough