You will be given a definition of a task first, then some input of the task.
In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Lignin makes up 15-30% of what structure?, Context: Wood is a heterogeneous, hygroscopic, cellular and anisotropic material. It consists of cells, and the cell walls are composed of micro-fibrils of cellulose (40% – 50%) and hemicellulose (15% – 25%) impregnated with lignin (15% – 30%).
Output:
cell walls