impatiently［im'pei？ntli］ad。 無耐性地
例句 Unlike most major inventions； photography had made people impatiently wait for a long time。 與大多數重要發明不同，長期以來人們都迫不及待地等待攝影技術的出現。
inability［？in？'bil？ti］n。 無能，無力
例句 All of the theories about the inability to recall early experiences are rejected。 所有關於無法回憶起以前經歷的理論都被否決了。
要點 inability一般表示“承擔某事物的能力、技能不足”。託福閱讀中還可能會用inpetence； incapacity等詞代替。
inadequate［in'？dikw？t］a。 不充分的；不適當的
例句 1。 When people first started to build； the structural methods which were used to provide strength and size were inadequate because they were not based on physical laws。 當人們最初開始建造的時候，有關力度和尺寸的建築方法都是不適當的，因為這些方法都沒有依據物理法則。
2。 Only after several inadequate breaths； resulting in the considerable elevation of carbon dioxide and reduction of oxygen in the blood； is breathing effort adjusted。 只是在幾次不充分的呼吸之後，血液中二氧化碳的含量適當增加，而氧氣的含量則有所減少，這樣呼吸才能被調整過來。
派生 inadequacy（n。 不適當）
inadvertently［？in？d'v？：rt？ntli］ad。 不小心地，非故意地
例句 mensal associations sometimes involve one species' obtaining food that is inadvertently exposed by another。 在共生關係中，有時當其中一個物種在獲取食物的時候，會被另一個物種無意中暴露出來。
incentive［in'sentiv］n。 刺激；動機
例句 1。 The incentive of the farmers who wish to conserve water is reduced because many of their neighbors are profiting by using great amounts of water。 農民希望節約用水的動機被減弱了，因為他們的許多鄰居都因大量用水而獲得了利益。
2。 There was incentive for American potters to replace the imports with parable domestic goods。 美國的製陶工人用質量相當的國產商品來替代進口