原始粗骨土，薄层腐殖质土

protospacer，proto-spacer

proto-oncogene

ras Proto-Oncogene Protein p21

proto-oncogene

erbB-1 Proto-Oncogene Protein

bcl-2 Proto-Oncogene Proteins

proto-industrialization[专业]工业

proto-; prot-