1.perennial a．長期的(perpetual);n．多年生植物(perennial plant)

詞根記憶：per+enn(年)+ial--年到頭的--長期的

例：perennial problem//The root systems of most flowering perennials always become too crowded.

派生詞：perennially( ad.長期地)

2.performance n.性能(the manner in which a mechanism performs)；表演(the action of representing a character in a play)：成績，績效(sth. accomplished)

詞根記憶：來自perform(v.執行；表演)

例：Such legislation would duplicate initiatives already being made by corporate boards to improve their own performance.

3.perfunctory a．草率的；敷衍的(lacking in care, interest or enthusiasm)

詞根記憶：per(表面)+funct(做)+ory--做表面功夫--敷衍的

例：Victorian criticism of works by women writers was perfunctory.

4.perimeter n．周長(the length of the outer edge of a closed geometric shape)

詞根記憶：peri(周圍)+meter(測量)--周長

例：The perimeter of the rectangular garden is 360 feet.

5.periodic a．周期的，定期的(occurring or recurring at regular intervals)

詞根記憶：來自period(n．周期)

例：They still display periodic behavior, continuing to burrow on schedule for several weeks.

派生詞：periodically( ad.定期地；周期性地)

同根詞：aperiodic(a．不定期的；非周期性的)

6.periodical a．周期的，定期的(periodic)；期刊的(published in，characteristic of, or connected with a periodical);門．期刊(a periodical publication)

例：The total of the expenditure for periodicals and newspapers was 25 percent less than the expenditure for books.

periodically( ad.周期性地)

7.periphery n.外圍(the outward bounds of something as distinguished from its internal regions or center)

詞根記憶：peri(周圍)+pher+y--帶到周圍--外圍

例：Most of the offices and classrooms were in the center of the college campus, and the dormitories were on the periphery.

派生詞：peripheral(a．外圍的)

8.perishable a．易腐敗的(likely to decay or go bad quickly);n．易腐敗的東西(stuff subject to decay)

詞根記憶：來自perish(v.腐爛)

例：Cooking is usually the final step in preparing food for consumption, whereas irradiation serves to ensure a longer shelf life for perishable foods.

派生詞：perishability(n.非持久性：易腐性)

同根詞：perisher (n.討厭的人；死亡之物)

9.permanent a．永久的(lasting)；固定的(stable)

聯想記憶：per(貫穿)+man(人類)+ent(…的)--貫穿人類歷史--永久的

例：The lssei(第一代移居北美的日本人)formed a permanent, family-based community.

派生詞：permanently( ad.永久地，固定地)