precipitant

n. 沉淀剂，adj. 突如其来的

precarious, precariously, precariousness, precaution, precautionary, precede, precedence, precedent, precedented, preceding, precentor, precept, preceptor, precession, precinct, preciosity, precious, preciously, preciousness, precipice, precipitate, precipitately, precipitation, precipitous, precipitously, precis, precise, precisely, preciseness, precision, preclude, preclusion, precocious, precociously, precociousness, precocity, precognition, preconceived, preconception, precursor, precursory,