"Gabby come on over here i have someone i want to introduce you to!... Gabby this is Joe, Joe this is Gabby." then they usually shake hands or something and say "nice to meet you Joe/Gabby :)" and if...
It depends on senairo , context , level ( age group of audience ) , for example if its a subjective introduction to some technology then u can start with a welcome message to audiences then say about...
Those solids which have the weak binding forces on heating directly convert in to gaseous state (without melting) this is known as the process of sublimation.