听力题 If you seize the stem of a nettle (荨麻) firmly, perhaps with the idea of uprooting a weed that is growing where it should not, you will probably feel a sharp sting in your palm or through the thicker part of your fingers. The stinging hairs on a nettle'' s stem are small but effective. It is not unusual to feel the sting for several hours after you touch the nettle. Long ago, when people made such lore part of their general knowledge, it was believed that you might rub the root of the nettle on the injury and the sting would disappear. The slender nettle, Urtica gracilis, is a wayside plant growing in moist soil over a wide area. It is more sparingly decorated with stinging hairs than the stinging nettle, U. dioica. Once full grown, the slender nettle may be quite safe to handle. The pliable young stems are more likely to be protected with stinging hairs than the stems of older plants. The American Indians found the nettle a useful plant. The fiber of the nettle is strong, and when spun together in several strands, it could be used to make twine for hobbling horses or weaving cloth.