What is cracking? from class 8

Cracking, in petroleum refining, the process by which heavy hydrocarbon molecules are broken up into lighter molecules by means of heat and usually pressure and sometimes catalysts

excellent.

"he is in cracking form to win this race"

Explanation:

a macro is a tool that allows you to automate tasks and add functionality to your forms, reports, and controls. for example, if you add a command button to a form, you associate the button's onclick event to a macro, and the macro contains the commands that you want the button to perform each time it is clicked.