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.
In this way, the ocean currents help regulate Earth's climate by facilitating the transfer of heat from warm tropical areas to colder areas near the poles. The water of the ocean surface moves in a regular pattern called surface ocean currents. On this map, warm currents are shown in red and cold currents are shown in blue. Image Credit: Windows to the Universe. The global wind patterns cause the surface currents to form in the uppers layer of the ocean. Where these winds blow in the same direction for long periods of time, large currents develop and transport vast amounts of water over long distances.