1.devise v.想出(to think out)；设计，发明(to invent)

例:Several procedures were devised to reduce transaction costs.

2.devoid a．(of)空的，缺乏的( absent)

词根记忆：de+void(空)一空的，缺乏的

例:The space between the galaxies is devoid of matter.

3.dexterity n.纯熟，灵巧(skill and ease in using the hands)

词根记忆：dexter(右)+ity一用右手做事--纯熟

例:Manual dexterity and mental alertness are lower in the late night than they are during the day.

4.diagnose v.诊断(to recognize a disease by signs and symptoms)

词根记忆：dia(穿过)+gnose(知道)--古时通过望、闻、问、切诊断病情，透过表面看实质一诊断

例:Angiograms(血管造影片)can be used to diagnose conditions other than blockages in arteries.

派生词：diagnosis(n.诊断)：diagnostic(a．诊断的;判断的)

5.diagnostic a．诊断的，判断的(of, relating to, or used in diagnosis);n．诊断程序(the art or practice of diagnosis)

词根记忆：来自diagnose(v.诊断)

例:Researchers have questioned the use of costly and experimental diagnostic tests to identify food allergies

6.diagonal n.对角线(a straight line than joins two opposite sides of sth. at an angle)

词根记忆：dia(穿过)+gon(角)+al_+穿过两个角的线-+对角线

例:The size of a television screen is given as the length of the screen's diagonal.

7.dialect n．方言，语调(a regional variety of language distinguished by features of vocabulary, grammar, and pronunciation from other regional varieties and constituting together with them a single language)

例:Cajuns speak adialect brought to southern Louisiana by the four thousand Acadians who migrated there in 1755.

8.diameter n.直径(a straight line segment passing through the center of a figure, especially of a circle or sphere, and terminating at the periphery)

词根记忆：dia（通过）+meter(量)--穿过它来测量直径--直径

注意：circumference(n.圆周长)

例:The diameter of the bicycle wheel was 0.5 meters.

9.diaper n.尿布

圆联想记忆：di(分开)+aper(看作paper纸)--能把水分隔开的纸--尿布

例:disposable diapers一次性尿布

10.dichotomy n.一分为二(a division into two especially mutually exclusive or contra-dictory groups)

词根记忆：dicho(二份)+tom(切、割)+y--切成二份--一分为二

例:the good bad dichotomy好与坏的二分法

派生词：dichotomous(a．二分的；分叉的)