1.efficacy n.功效，效力(the capacity or power to produce an effect)

例：Patients' ages may affect a treatment's efficacy.

同根詞：efficient(a．有效率的)

2.efficiency n.效率，功效(the quality or degree of being efficient)

詞根記憶：來(lái)自efficient(a．有效率的)

例：production efficiency生產(chǎn)效率

派生詞:inefficiency(n.無(wú)效率;無(wú)能)

3.efficient a．有效率的(being or involving the immediate agent in producing an effect)；有能力的(competent)

聯(lián)想記憶：ef（姨夫）+fici(做事)+ent(形容詞后綴)--姨夫做事很有效率--有效率的

例：Automobiles become less fuel efficient and therefore contribute more to air pollution as they age.

派生詞：efficiently(ad.有效地；高效地)

同根詞：efficacy(n.功效，效力)

4.effigy n.雕像,肖像(an image or representation especially of a person)

詞根記憶：ef(出)+fig(塑造)+y--塑造出外形--雕像

例：The objects found in the excavated temple were small terracotta(赤土陶器的)effigies.

同根詞：figment(n.虛構(gòu)的事)；figure(n.形體)

5.effluent n.支流（an outflowing branch of a main stream or lake）；廢水(waste liquid)

詞根記憶：ef（出）+仙(流)+ent--流出來(lái)的--支流

例：The factory generates the largest quantities of effluents.

6.egalitarianism n.平等主義(a belief in human equality especially with respect to social, political, and economic rights and privileges)

詞根記憶：來(lái)自egalitarian(a.平等主義的)

例：racial egalitarianism種族平等主義

7.egoistic a.自我主義的，利己主義的(believing that individual self-interest is the actual motive of all conscious action)

詞根記憶：ego(我)+istic--以我為中心的--自我主義的

例：The youth tend to translate the indMdualistic and humanistic goals of democracy into egoistic and materialistic ones.

8.eject v.噴射;驅(qū)逐(to throw out)

詞根記憶：e（出）+ject(扔)--被扔出來(lái)--噴射

例：A meteor stream is composed of dust particles that have been ejected from a parent comet.

派生詞：ejection(n.噴出，噴射)

9.elaborate a.精心制作的(planned or carried out with great care)v.詳述，詳細(xì)制定(to work out in detail)

聯(lián)想記憶：e（出）+labor(工作)+ate--辛苦勞動(dòng)做出來(lái)--精心制作

例：The first paragraph introduces a general thesis that is elaborated on in detail elsewhere in the passage.

派生詞：elaborately(ad.苦心經(jīng)營(yíng)地，精巧地)

10.elective n.先修課(an elective course or subject)；a.選修的(optional)

詞根記憶：e（出）+lect(選擇)+ive--選擇出--選修課

例：Home economics is only an elective, and few students choose to take it.//elective course選修課