A.乙烯 B.丙烯 C.丁烯 D.丁二烯
A.U1=73.3V B.U1=60.3V C.U1=110V D.U1=30.3V
A.空氣進(jìn)入 B.壓脂層亂層 C.再生壓力波動(dòng) D.樹(shù)脂層亂層
A.電導(dǎo)率升高 B.HSiO3-含量增大 C.pH值升高 D.堿度增大
A、樹(shù)脂呈淺綠色為陽(yáng)樹(shù)脂,樹(shù)脂不變色為陰樹(shù)脂 B、樹(shù)脂呈淺綠色為陰樹(shù)脂,樹(shù)脂不變色為陽(yáng)樹(shù)脂 C、樹(shù)脂呈淺綠色為陽(yáng)樹(shù)脂,樹(shù)脂深綠為陰樹(shù)脂 D、樹(shù)脂呈深綠為陽(yáng)樹(shù)脂,樹(shù)脂淺綠為陰樹(shù)脂
A.濕真密度 B.濕視密度 C.干真密度