新概念英语三册 Lesson53 In the public interest第（1）套课件下载

evolve  v.   逐渐形成
evolve a system for doing sth
形成了发展了一套…的体系
evolve from  演化
--Man has evolved from the ape(类人猿).
competent 
有资格去做某事
be competent to do sth..
be competent for sth..
safeguard   v./n.保护(正式,书面语或严肃大的场合下)
--We must safeguard our motherland.