1.deplete v.倒空，耗盡(to drain．to exhaust)

詞根記憶：de（去除）+plete（滿）一使不滿一倒空

例:A se ries of costly wars haddepleted the national treasury.

派生詞：depletion（n.損耗）

2.depletion n.消耗，損耗(the act of decreasing sth．markedIy)

來自depIete（v.耗盡，倒空）

例:Unlike cod and haddock, there are no legal size limits on catching monkfish, which contributes to its depletion by being overfished.

同根詞：complete(v.完成;a.完整的)

3.deposit v.儲蓄(to put in a bank);放置( to place)；n.存款(money deposited in a bank)；押金(money given as a pledge or down payment)；沉積物 (something laid down)

詞根記憶：de（起強調作用）+posit(放)一把財物妥善保管一儲蓄

例:Most of the gold deposits discovered during the original gold rushes were exposed at the Earth's surface.//Ms. Fox deposited $10,000 in a new account at the annual interest rate of 12 percent.

派生詞：depositor(n．存款人)：depository(n.存放處)

4.deprecate v.反對( to disapprove)；藐視(to belittle)

詞根記憶：de(去除)+prec( =preci價值)+ate -去掉價值--藐視

例:They deprecate the numerous Native American cultures.

5.depreciation n.貶值（falling in value）

詞根記憶：來自depreciate(v.貶值)

例:Because of rapid technological change,computers have a fast depreciation.

同根詞：appreciate(v.賞識)

6.depress v.使沮喪(to sadden)；削弱(to lessen the activity or strength)；使蕭條(to decrease the market value or marketability)

詞根記憶：de（往下）+press(壓)--往下壓一削弱

例:Adenosine(腺苷)normally depresses neuron firing in many areas of the brain.//Putting such large amounts of stock on the market would only depress its value.

派生詞：depressed(a．沮喪的，消沉的)；depression(n.抑郁;蕭條)；depressive（a.令人沮喪的;抑郁的）

7.depression n.消沉(dejection)；蕭條（期）

詞根記憶：來自depress(v.消沉，沮喪)

例:Only one percent of Americans born before 1905 suffer major depression by the age of seventy-five.//the Great Depression大蕭條

派生詞：depressive(a．郁悶的)

8.deprivation n．剝奪(the act or an instance of depriving);缺乏(the state of being deprived)

詞根記憶：來自deprive(v.剝奪)

例:Sleep-deprivation is not used to treat depression.//oxygen deprivation缺氧

同根詞：privacy(n.獨處，私下);privation(n.貧乏)

9.deregulation n.違反規定，撤銷管制規定(the act or process of removing restrictions and regulations)

詞根記憶：來自deregulate（v.解除對…的管制）

例:Since the deregulation of airlines, delays at the nation's increasingly busy airports have increased by 25 percent.

同根詞：regulation(n.規則；校準)

10.derivative a．派生的(derived)；無創意的(not original);n.轉成物

例:The Madagascar periwinkle has a derivative which has proved useful in decreasing mortality among young leukemia patients.

同根詞：derivation(n.引出；來歷；詞源)