单项选择题
A.清洁中段尿培养,菌落计数为500个/ml B.清洁中段尿培养,菌落计数为1000个/ml C.清洁中段尿培养,菌落计数为1万个/ml D.清洁中段尿培养,菌落计数为5万个/ml
A.snRNA B.mRNA C.tRNA D.hnRNA