callus pad造句

• The nearly smooth surface has a blotched periphery and a central tubercle on the callus pad distinguish it.
• Sieve-tube members that are alive contain a polymer called callose, a carbohydrate polymer, forming the callus pad / callus, the colourless substance that covers the sieve plate.
• The handle of the club runs diagonally across the base of the fingers on my left hand, from the base of the forefinger to a point atop the callus pad below my little finger.