Here is the full solution for CraftConnections Day 72. Each group is shown with its difficulty colour and a redundant shape, so it stays readable if you are colour blind.
Classic — Day 72
● Pickaxes Copper Pickaxe · Golden Pickaxe · Iron Pickaxe · Wooden Pickaxe
▲ Boots Golden Boots · Leather Boots · Iron Boots · Netherite Boots
◆ You mine these with an axe Oak Shelf · Ladder · Acacia Shelf · Bookshelf