What does ob in front of a date mean?

Does sea salt contain nickel? In 1885 what arrived stateside in 350 individual pieces in more than 200 boxes? How does a ship find its location? What was the gallery above the stage used for? Can you use your TWIC card for discounts on Disneyland tickets? Do carrots grow in the rainforest? How do oceanographer measure the salinity or ocean water? What is the worlds talest roller coasters? When was CP Nel Museum created? What is a company who dumps chemicals into a river called? How many Africa hectares of rainforest have been given to the logging company? Why was Mount Rushmore built? Where is the Johnstown Flood Museum Association in Johnstown Pennsylvania located? In which British series did Hugh Laurie star before finding fame on House? What bridge goes over the Mississippi River? Which country in Asia is just south into the Indian Ocean? What seas border china? Are coral animals plants or mineral? Is Leeds Castle a motte and bailey castle or a stone keep castle? Can cedar chips absorb odors?