2. change=shift=alter=transfer 改变v.

　　3. establish=build=found=set up=start 建立 v.

　　4. official=authority=leader=supervisor 官员 n.

　　5. isolated=inaccessible=distant=remote=faraway 隔离的, 边远的 adj.

　　6. collapse=fall=fall over=fall down 倒塌 v.

　　7. destroy=devastate=wreck=obliterate 毁灭 v.

　　8. absorb=digest=take in=assimilate 吸收 v.

　　9. severe=serious=stiff=heavy 严重的 adj.

　　10. purify=refine=distill 净化 v.

　　11. hidden=disguised=concealed=veiled 隐藏的 adj.

　　12. decline=decrease=reduce=fall=drop 下降 v.

　　13. deteriorate=get worse=go down=decline 变坏 v.

　　14. recognize=know=identify=pick out 认出 v.

　　15. conclude=summarize=come to/reach the conclusion 得出结论 v.

　　16. adapt to=get used to=become accustomed to=adjust to 适应 v.

　　17. initiate=start=launch=open=set in motion 开始，发起 v.

　　18. refer to=mention=allude to=touch on 提到 v.

　　19. identify=name=recognize=diagnose 确定，认同 v.

　　20. request=demand=claim=petition=appeal 要求 n.

　　21. be divided into=separate=split=break up=break down 分开 v.

　　22. consist of=be made up of=be composed of=comprise 由…组成23. hinder=hamper=impede 阻碍 v.

　　24. objective=aim=purpose=goal=target 目标 n.

　　25. implement=carry on=execute=put sth. Into practice 实行 v.

　　26. promote=encourage=help=aid 促进 v.

　　27. warn=caution=alert=give sb. a warning 警告 v.

　　28. observation post=watchtower 瞭望塔 n.

　　29. access=entrance=entryway=way in 通路，进入 n.