Context: Drying produces a decided increase in the strength of wood, particularly in small specimens. An extreme example is the case of a completely dry spruce block 5 cm in section, which will sustain a permanent load four times as great as a green (undried) block of the same size will.

Question: What will drying often increase in wood?
Answer: strength

Question: What color is also used interchangeably with "undried" for wood?
Answer: green

Question: What type of wood can hold four times as much of a load when dried?
Answer: spruce