With Best Regards: Closing Your Letter. June 17, 2014 by. When writing professional or informal emails and letters, it is often considered proper etiquette to complete your correspondence with an appropriate closing signature.
What two conditions are needed for clouds to form? Air must be cooled to its dew point and particles must be present in the air When are clouds formed by ice crystals instead of drops of liquid water?
Clouds form when the air is saturated and cannot hold any more water vapour, this can happen in two ways: 1  The amount of water in the air has increased-for example through evaporation-to the point that the air cannot hold any more water.