单项选择题

Flax has been raised for many thousands of years, for many different reasons. Probably the two most important reasons are for the fabric made from it and the oil produced from it. The woody stem of the flax plant contains the long, strong fibers that are used to make linen. The seeds are rich in an oil important for its industrial uses.
The people of ancient Egypt, Assyria, and Mesopotamia raised flax for cloth; Egyptian mummies were wrapped in linen. Since the discovery of its drying ability, the oil from flaxseed, called linseed oil, has been used as a drying agent in paints and varnishes.
The best fiber and the best seed cannot be obtained from the same kinds of plant. Fiber flax grows tall and has few branches. It needs a short, cool growing season with plenty of rainfall evenly distributed. Otherwise, the plants become woody and the fiber is rough and dry. On the other hand, seed flax grows well in places that are too dry for fiber flax. The plants are lower to the ground and have more branches.
Which of the following questions is answered by the passage