7. The scab on the tree was a sign that it had been damaged before.(树上的痂是它以前受过伤的标志。) 8. “If you keep scratching the scab, it'll never go away,” my sister warned me.(“如果你一直挠那个痂,它永远都好不了,”我姐姐警告我。) 9.
Water is far and away the most common cause, though in this case the color change is just temporary. Scabs are the body’s way of protecting skin as it heals, basically by creating a natural bandage that “seals” the area from environmental elements and stops surface bleeding. They aren’...