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

詞根記憶：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.

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

2.inspection n.．檢查（examination）；視察

例：safety inspections安全檢查 ’

3.inspector n.檢查員(a person employed to inspect sth.);巡視員（a police officer who is in charge of usually several precincts and ranks below a superintendent or deputy superintendent)

詞根記憶：來自inspect(v.檢查：觀察)

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.

同根詞：spectator(n．觀眾)

4.inspiration n.啟示，靈感(thought or emotion inspired by sth.)

聯想記憶：in（進入）+spir(呼吸)+ation--吸入（靈氣）--靈感

例：sudden inspiration靈機一動

同根詞：expiration(n.呼氣；屆滿)

5.instaii v.安裝，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.

派生詞：installation(n.安裝，安置)；installment(n．分期付款)

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

詞根記憶：install(安裝)+ation--安裝

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.

同根詞：installment(n．分期付款：安裝)

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

詞根記憶：instant(馬上的，立即的)+aneous--即時的

例：The explosion caused instantaneous destruction.

派生詞：instantaneously( ad.即時地，瞬間地)

8.instill v．逐漸灌輸(to impart gradually, implant)

詞根記憶：in（進入）+still(水滴)--像水滴一樣進入--逐漸灌輸

例：Courtesy must be instilled in childhood.