context: In grading lumber and structural timber, knots are classified according to their form, size, soundness, and the firmness with which they are held in place. This firmness is affected by, among other factors, the length of time for which the branch was dead while the attaching stem continued to grow.
question: స్థిరత్వం, దృఢత్వం, రూపంతోపాటు, ముడిపడివున్న ఏ లక్షణాన్ని వర్గీకరిస్తారు?
answers: size