The word petroleum (literally "rock oil" from the Latin petra, "rock" or "stone," and oleum, "oil") was first used in 1556 in a treatise published by the German mineralogist Georg Bauer, known as Georgius Agricola.
Don't panic – there's a plan This, argues Petra Schleiter, associate politics professor at Oxford, has the benefit of following "democratic and electoral logic".
Blue Peter viewers will see the final part of Project Petra when the show airs next Thursday at 5pm.
Raja Petra Kamarudin, fellow at the Institute of Southeast Asian Studies, wrote on Malaysia Today, a website the Malaysian government is trying unsuccessfully to block: "Anwar has to balance the aims of the parties in his coalition, and we will see compromises being made.
"It's a national institution," says Petra Henning, a classical music fan who runs a café nearby the Philharmonie.
Safarova's compatriot Petra Kvitova now leads the chasing pack, having replaced Maria Sharapova in the No2 slot.
When Li Na recently tipped Petra Kvitova to win this year's Australian Open, she did so not just because of their close friendship and the respect she has for the Czech's game.
But two of them were pretty good efforts; she defeated Sabine Lisicki in Madrid, and took eventual champion Petra Kvitova to three sets in her next match.
Williams will start as the overwhelming favourite but has plenty of respect for Bacsinszky, not least since she beat the Wimbledon champion, Petra Kvitova, in the fourth round.
When it comes to online submissions, viewers' names are rather more exotic – Banana Diamond Koala, for instance, has contacted the show about x-ray glasses, as part of today's launch of Project PETRA, a competition whose winners will be trained as spies by actual MI5.
The historic occasion was part of a competition called Project Petra, held for children interested in spies and the intelligence services.
