chemicalpureadj.化学纯的chemicaladj.化学的n.药品；化学物chemical compatibilizer化学增容剂chemical fire retardant化学阻燃剂chemical water analysis水的化学分析chemical cleaning agent化学清洗剂chemical derivatization化学衍化chemical control method化学控制法chemical characteristic化学特性chemical etch polishing化学腐蚀抛光chemical transfer laser化学转移激光器chemical product tanker化学品船