prerequisite

n.必备条件，先决条件，前提

preoccupy, prep, prep school, preparation, preparation for, preparatory, prepare, prepared, preparedness, prepay, prepayment, preponderance, preponderant, preponderate, preposition, prepositional, prepositional phrase, prepossessing, preposterous, preposterously, prerequisite (also pre-condition), prerogative, Pres, presage, Presbyterian, Presbyterianism, presbytery, preschool, prescience, prescient, prescribe, prescribed, prescript, prescription, prescriptive, prescriptively, presence, present, present participle, presentable,