¿ Que es un sistema de comunicacion ?

Whats three fourths of 15(this is supposed to be in math but i clicked too fast)

Drag the tiles to the correct boxes to complete the pairs. match the errors with their definitions. #name #value #ref when a formula produces output that is too lengthy to fit in the spreadsheet cell arrowright when you enter an invalid cell reference in a formula arrowright when you type text in cells that accept numeric data arrowright when you type in a cell reference that doesn’t exist arrowright reset next

What is html ? give a small description about html