Comprehension
Passage 2
The walnut tree produces wood that is used for countless
purposes, and is considered the finest wood in the world. The wood is easy to
work with, yet it is very hard and durable—and when it is polished, it produces
a rich, dark luster. It also shrinks and swells less than any other wood, which
makes it especially desirable for fine furniture, flooring, and even gun
stocks. In fact, just about every part of the walnut is unusually hard and
strong. The nut of the tree is encased inside a very hard shell, which itself
is enclosed in a leathery outer covering called a husk. It requires real effort
to break through those layers to get at the tasty meat inside. Yet every part
of the walnut is useful to people. The outer husk produces a dark reddish stain
that is hard to remove from the hands of the person, who opens the nut, and
this pigment is widely used in dyes and wood stains. The inner shell is used as
an abrasive to clean jet engines. And the meat of the nut is extensively used
in cooking, ice cream, flavorings—and just eaten raw.
Walnut trees exude a chemical into the soil near their roots
which can be poisonous to some trees and shrubs. Fruit trees, for example, will
not survive if planted too close to a walnut. Many other plants, such as maple
trees or ivy, are not affected by the walnut’s presence, and are well-suited to
grow in its vicinity. [24131]
