Double click a sheet tab and you can rename it (or right click and select rename).
You will have to call one of them SheetX or similar whilst you do the adjustments as 2 sheets cannot have the same name.
OnePlus 5T review: Hands-on
Illustrator Andrés Lozano on his improv line work, brazen use of colours & hand sketching
iPhone X review
Comment envoyer gratuitement des gros fichiers ?