1.obsolete和obsolescent
obsolete(no longer in use or already out of date)“已废弃的，已不用的”; an obsolete vessel废舰;an obsolete word已废的词。
obsolescent (going out of use or becoming out of date)“逐渐被废弃的，快要不用的”;Do you think that faxes are obsolescent?
2. officious和official
officious“爱管闲事的”，“非正式的”;an officious statement非正式声明。official“官方的”，“公务上的”; an official gazette官方通报;an official letter公函,公文;an official record正式记录
3.peaceable和peaceful，peaceable (peaceloving, mild, placid, not inclined to quarrel or fight or existing in peace)“平和的”;“温和的”;“温顺的”。peaceful“和平的，太平的”;“宁静的”;“爱好和平的”;a peaceful night's sleep ; peaceful coexistence和平共处;peaceful uses of atomic energy原子能的和平应用。
historic与historical
historic: famous in history, 历史上著名的
historical: belong to history 历史上的
electric与electrical
electrical: worked by, changed with， 用电的，带电的, 有电的
～ current cable
electrical: ～ engineering apparatus
economic与economical
economic: of economics
～ policy geography crisis crops
economical: careful in the spending of money 经济的，节俭的
an ～ housewife store
industrial与industrious
industrial: of industries 工业的
the ～ revolution products system
industrious: hard-working 努力的
～ people
considerable与considerate
considerable: great much 相当多(大)的
a ～ income distance
considerate: thoughtful 体谅的，
She is ～ to others.
sensible与sensitive
sensible: reasonable, 实用的， 明知的
a ～ woman idea 豁达的妇女 明知的观点
～ clothes 实用的衣服
sensitive: quick to receive 敏感的
a ～ skin
～ paper 感光纸
