estimate
n. 估计, 估价；报价； 判断
vt. & vi. 估计; 评价, 评估
搭配：at a rough estimate 据大致估计
by estimate 依照估计
辨析：estimate 意为估计，assess，evaluate都意为估价，评估。
1.The painter's estimate for painting the whole house was 1000 dollars.
油漆匠对油刷整个房子的估价是1000美元。
2.We got estimates from three different contractors before accepting
the lowest.
我们得到三个承包商的报价后, 接受了最低的报价。
3.I don't know her well enough to form an estimate of her abilities.
我对她不太了解, 无法对她的能力做出判断。
4.The gardener estimated that it would take him four hours to weed the
garden.
园丁估计他给花园除草需要四个小时。
evolve
vt. & vi. 演变; 进化
辨析：involve 卷入，陷入；涉及
revolve 使旋转
1.Language is constantly and gradually evolving.
语言在不断地缓慢发展。
2. We can evolve the truth from a mass of confused evidence.
我们可以从复杂的证据中推断事实真象。
existence
n. 存在 ；生存, 生活(方式)
搭配：come into existence 出现，产生
bring...into existence 使...出现，产生
1.He does not believe in the existence of ghosts.
他不相信有鬼存在。
2.Trees owe their existence to soil.
树木靠土壤生存。
factor
n. 因素, 要素 ；〈数〉因子, 因数
1.Industry and modesty are the chief factors of his success.
勤奋和谦虚是他成功的主要因素。
2.3 is a factor of6.
3是6的因数。
