1.insomnia n.失眠(chronic inability to fall asleep or remain asleep for an adequate length of time)

词根记忆：in（不）+somn(睡眠)+ia(病)--不能入睡的病--失眠

例：Any combination of overwork and stress inevitably leads to insomnia.

同根词：somniferous(a．催眠的)；somnolent(a．想睡的)

2.inspection n.．检查（examination）；视察

例：safety inspections安全检查 ’

3.inspector n.检查员(a person employed to inspect sth.);巡视员（a police officer who is in charge of usually several precincts and ranks below a superintendent or deputy superintendent)

词根记忆：来自inspect(v.检查：观察)

例：No matter how patiently they explain their reasons for confiscating certain items, customs inspectors are often treated by travelers as if they were wanton poachers rather than government employees.

同根词：spectator(n．观众)

4.inspiration n.启示，灵感(thought or emotion inspired by sth.)

联想记忆：in（进入）+spir(呼吸)+ation--吸入（灵气）--灵感

例：sudden inspiration灵机一动

同根词：expiration(n.呼气；届满)

5.instaii v.安装，安置( to set up for use or service)

例：Some residents in the community have installed a solar-energy system on the roof of their houses.

派生词：installation(n.安装，安置)；installment(n．分期付款)

6.installation n．安装(the act of installing)；装置(sth. that is installed for use)

词根记忆：install(安装)+ation--安装

例：Since the installation of the alarms, the average number of porpoises caught in the company's nets has dropped from eight to one per month.

同根词：installment(n．分期付款：安装)

7.instantaneous a.即使的(immediate, at once)

词根记忆：instant(马上的，立即的)+aneous--即时的

例：The explosion caused instantaneous destruction.

派生词：instantaneously( ad.即时地，瞬间地)

8.instill v．逐渐灌输(to impart gradually, implant)

词根记忆：in（进入）+still(水滴)--像水滴一样进入--逐渐灌输

例：Courtesy must be instilled in childhood.