1.delta n.（河流的）三角洲(the alluvial deposit at the mouth of a river)

词根记忆：本身是希腊语的第四个字母“△”，也指形状像△的河流的三角洲

例:The Hyksos(希克索斯王)invaded the Nile Detta of Egypt and ruled it from 1650 B.C.

2.deluxe a．豪华的( notably luxurious, elegant, or expensive)

词根记忆：de+luxe(光)一闪闪发光的一豪华的

例:Our company started manufacturing and marketing adeluxe air filter six months ago.

3.delve v.钻研，深入探索(to make a careful search for information)

联想记忆：整天埋在书架(shelves)里钻研(delve)

例:The investigator delved into the matter of Tom's sudden wealth.

4.demobilization n.遣散（军人）（discharging from military service)；复员

词根记忆：来自demobilize(v.复员)，de+mobilize(动员)--动员回家--复员

例:The bill was passed to help the nation's demobilization effort.

同根词：mobility(n.能动性)

5.democracy n.民主,民主主义;民主政治(government by the people)

词根记忆：demo(人民)+cracy(统治)一人民统治一民主

例:Many scholars have theorized that economic development, particularly industrialization and urbanization, contributes to the growth of participatory democvacy.

同根词：demography(n.人口统计学)

6.democrat n．民主主义者(an adherent of democracy); [D-]美国民主党人

词根记忆：demo(人民)+crat一民主主叉者

例:A certain state legislature consists of 124 members, each of whom is either a Democrat or a Republican.

派生词:democratic(a.民主的：民主主义的)：democratically(ad.民主地：民主主义地)

7.demographer n.人口统计家( expert in demography)

词根记忆：demo(人民)+graph（写）+er一人口统计学家

例:Demographers are doing research for an international economics newsletter claim.

派生词:demographic(a．人口统计的)

8.demographic a.人口缬渗心擎台9(of de-mography or demographics)

词根记忆：demo(人民，人口)+graph(写，画)+ic--描写人口状况的--人口统计学的

例:The researchers dismissed demographic bias because older individuals were not overrepresented in the fossil samples.

同根词：democracy(n.民主)

9.demonstrably ad.可证实地，显然地(apparently, evidently)

词根记忆：来自demonstrable(a．可论证的，可证实的)

例:That demonstrably slowed the economic growth of medieval France.

10.demonstrate v.证明(to prove by reasoning or evidence)；显示(to show clearly)；示威游行（或集会）(to make a demonstration, to participate in a public display of opinion)

词根记忆：de（加强）+monstr(表示)+ate(做)一加强表示一证明

例:Her work aims to demonstrate that wage work enabled women to become aware of themselves as a distinct social group.//The citizens demonstrated against the new taxes.

派生词:demonstrator(n.示威者；论证者)