1.precede v.在…之前，早于（to be earlier than）

詞根記憶：pre(前)+cede(走)--走在前面--在…之前

例：Leibniz' notes are limited to early sections of Newton's book, sections that precede the ones in which Newton's calculus concepts and techniques are presented.

同根詞：precedent(n.先例：a．在前的)

2.precedence n.優先，居先(the fact of preceding in time)

詞根記憶：pre(前)+ced(走)+ence--走在前面--優先

例：The water rights of the inhabitants of the Fort Berthold Indian Reservation would not take precedence over those of other citizens.

同根詞：precedential(a．有先例的)

3.preceding a．在前的( to surpass in rank, dignity, or importance)

詞根記憶：來自precede(v.領先，在…前面)

例：Present information contradicts the preceding paragraph.

同根詞：precedent(a．在前的；n．先例)

4.precipitate v.加速，促成(to bring about abruptly; hasten)a.魯莽的(impetuous)

詞根記憶：pre(預先)+cipit(落下)+ate--先落下了--加速

例：However, since humans tended to migrate to areas as the climate in those areas began to warm, the extinctions might have been precipitated by the climatic warming rather than by human migration.

派生詞：precipitation(n．沉淀；沉淀物)

5.precipitation n.沉淀（the quality or state of being precipitated）；沉淀物(sth. precipitated)

詞根記憶：來自precipitate(v.使…沉淀；促成)

例：The continental United States receives an average of 30 inches of precipitation a year.

同根詞：precipitant(n．沉淀劑)

6.precise a．準確的，精確的(exact)；嚴謹的（strict）

詞根記憶：preci(價值，價格)+se--定價一般都很精確--準確的，精確的

例：The witness gave a precise account of the murder.//precise statement嚴謹的陳述

派生詞：precision[n.精確，精密（度）]

7.precursor n．先驅;先兆;前身(forerunner, predecessor,a substance from which another substance is formed)

詞根記憶：pre(前)+curs(跑)+or--跑在前面的人--先驅

例：Lightning is a precursor of thunder.

8.predate v.居先，早于(antedate)

例：Some North American sites of human habitation predate any sites found in South America.