Quotation marks, also called 'inverted commas', are of two types: single and double. British practice is normally to enclose quoted matter between single quotation marks, and to use double quotation marks for a quotation within a quotation:
The oceans absorb the sun's heat, transferring it to the atmosphere and distributing it around the world via the ever-moving ocean currents. This drives global weather patterns and acts as a heater in the winter and an air conditioner in the summer.
ocean currents on marine life consists of the enhancement of primary productivity, and that is the reason why this article is placed within the Topic Productivity of the Oceans. This is so because primary production in the ocean is limited by availability of light and