ensure
vt.保证，担保，确保
A new computer system entails a lot of retraining.使用新的计算机系统需要大量的再培训。
entail
vt.使承担，使成为必要，需要
Lithuania was the first of the Soviet republics to declare independence(= officially state its independence). 立陶宛是苏联诸多共和国中第一个宣布独立的。
independence
n.独立，自主，自立
There are plans to split the corporation into a number of smaller independent companies.有计划要把大企业分割成一些独立的小公司。
independent
a.独立的，自主的;中立的;无关的
The changing size of an infant’s head is considered an index of brain growth.婴儿头部尺寸的不断变大标志着大脑在发育。
index
n.索引;标志，表征;指数(标) vt.编索引She lost the election by a mere 20 votes.她以仅仅 20 票之差落选。
