Violin-makers have always known that the secret of the quality
instrument lies in the selection of the wood. Maple wood is preferred
for the back, ribs, and neck of the instrument, while spruce is often
used for the top. These woods have superior acoustical and mechanical
properties, having the least loss of energy through internal friction,
compared to other woods. For example, spruce cells are light,
physiologically simple, hollow, and rigid---ideal properties for
enhanced acoustic quality. Only trees that have grown in thin, poor
soils at higher elevations on north-facing slopes have the dense wood
grain that helps instill a superior tone in violins. Long winters and
cool summers produce wood that has the slow, even growth ideal for
producing quality sounding boards.
1. Which **TWO** of these factors are mentioned in the passage as possibly having a significant effect on the eventual quality of a violin?
请选择 2 个答案
A. The altitude at which a tree is grown.
B. The stage of a tree's growth at which it is cut down.
C. The steepness of the mountains where a tree is grown.
D. The lack of rain during a tree's growing period.
E. The nutritional composition of the earth in which a tree is grown.