1. effective [ɪ'fektɪv]  
adj. 有效的，起作用的；实际的，实在的；给人深刻印象
The government should take effective measures to live through this economical crisis.  政府应采取有效的措施度过这场经济危机。

2. efficient [ɪ'fɪʃ(ə)nt] 
adj. 有效率的；有能力的；生效的
With today's more efficient contraception women can plan their families and careers. 有了当今更为高效的避孕方法妇女们能够规划好自己的家庭和事业。

3. justify ['dʒʌstɪfaɪ] 
vi. 证明合法；整理版面；替…辩护
No argument can justify a war. 没有任何理由能证明一个战争有理。

4. testify ['testɪfaɪ]  
v. 证明，证实；作证
Several eyewitnesses testified that they saw the officers hit Miller in the face. 几个目击者证明他们看到那些警察们打了米勒的脸。

5. verify ['verɪfaɪ] 
vt. 核实；查证
I verified the source from which I had that information. 我核实了我获知那条信息的来源。

6. confirm  [kən'fɜːm] 
vt. 确认；确定；证实；批准；使巩固
The spokesman confirmed that the area was now in rebel hands. 该发言人证实该地区现在处于反叛者的控制之中。

7. affirm [ə'fɜːm]  
vt. 肯定；断言；证实
The court affirmed that the information can be made public under the Freedom of Information Act. 法院公开肯定了此信息能依据《自由信息法案》公之于众。

8. underlie  [ʌndə'laɪ]  
vt. 成为……的基础；位于……之下
The principles which underlie our foreign policy are sound. 作为我们外交政策基础的原则是健全的。

9. puzzle ['pʌz(ə)l]  
v. 使…困惑；使…为难；苦思而得出n. 谜；难题；迷惑
I've been puzzling over all the figures, trying to find what happened to the missing money. 我一直在反复琢磨这些数字，力图找出少了钱的原因。

10. confuse [kən'fjuːz]  
vt. 使混乱；使困惑
You have confused the meanings of the two words. 你把这两个词的意思弄混了。