1.validity n．有效性；合法性(state of being legally acceptable)；正确性(state of being right)
例：The validity of a new scientific finding was questioned by most scientists.
2.vanish v.消失(to pass quickly from sight)
例：Of the five hundred million different species of living creatures that have appeared on Earth, nearly 99 percent have vanished.
3.variable n．可变物(something that is variable)；变量，变数(a quantity that may assume any one of a set of values)
例：The key variables driving costs are size and type of order.
4.variation n．变化：变异（the act or process of varying）
例：There is a considerable degree of variation in shade of color between weeds of different species.
5.varsity n．大学(university)；大学代表队（尤指体育）(the principal squad representing a university, college, school, or club especially in a sport)
例：Their level of participation in extracurricular activities and varsity sports is unusually high.
6.vegetarian n.素食者(one who believes in or practices vegetarianism);a．素食的(consisting wholly of vegetables fruits, grains, nuts, and sometimes eggs or dairy products)
例：Vegetarians refer to those whose diet consists of plant products only.//The diet of the ordinary Greek in classical times was largely vegetarian.
7.vegetation n．植被(plant life or total plant cover( as of an area))
例：The relationship between vegetation and climate is not direct.
8.vegetative a.植物的，有关植物生长的(relating to, composed of，or suggesting vegetation)
例：A plant's fecundity is high if it can reproduce quickly by means of vegetative growth.
9.vein n.纹理(texture)；矿脉(a regularly shaped and lengthy occurrence of an ore);静脉(a blood vessel that carries blood from the capillaries toward the heart)
例：A gold-quartz vein system originates in magmatic fluids.