1．The company has better products than its ________ (竞争者)．
答案：competitors
2．He gave an answer to my letter ________ (迅速地)．
答案：swiftly
3．A long time ago， many black people were taken to America as ________ (奴隶)．
答案：slaves
4．He did not seem to be experienced enough to ________ (取代) his father．
答案：replace
5．The teacher who ________ (自愿) to teach in the poor village school was spoken highly of by many people．
答案：volunteered
6．Paper is one of the greatest inventions in a________ China．
答案：ancient
