A.用質(zhì)量份數(shù)B.用質(zhì)量百分數(shù)C.以體積百分數(shù)D.體積分數(shù)
A.單因素與空白對照B.多因素與空白對照C.單因素與多因素
A.實用、廉價、高效B.實用、高效、經(jīng)濟C.實用、性能好、經(jīng)濟D.高效、經(jīng)濟、性能好