Please choose the correct ending to complete the given sentence: Education and Communications: [header] How to identify oaks by the acorns [title] Examine the acorn cup scales. [step] The nut of the acorn grows from a woody cup, which may remind you of a hat. The small scales that make up the cup may be thin and flat, or thick and forming wart-like growths (tubercles).

Ending1: [substeps] The size of these growths vary widely-from 2.5 to 7 millimetres. They have a gorgeous shine and can help define oaks. Ending2: This variation is a great start for narrowing down the possible species. [substeps] All oaks native to north america and europe have a spiral of overlapping scales on the cup. Ending3: The acorn cup scales are what you typically see on acorn balls. These growths are often purplish-purple in color, and have specific cracks or fissures to them. Ending4: These growths will look like small parallel bumps surrounding the acorn cup, hiding the acorn cup scales beneath. Be careful not to access these growths with pliers.

Answer format: ending1/ending2/ending3/ending4