For lumber it is where it is rainy but not flooding in rain because if it is flooded in rain it will have rotten layers inside making it bad to use and will not be safe to use.
Think of a piece of paper that is enhanced to grow forever. This would
fit the definition of a plane. A plane is a flat surface that has no
thickness. A plane contains an infinite number of lines and extends
without end in the directions of its lines.
Despite his nature of giving, Musa's massive spending and generous donations created a massive ten year gold recession. In the cities of Cairo, Medina, and Mecca, the sudden influx of gold devalued the metal significantly. Prices of goods and wares became greatly inflated.
I hope his helps!! :))