分流道设计时,热塑性塑料用圆形截面分流道,直径一段取d=2~10mm,流动性很好的(),可取较小截面。
A.硬聚氯乙烯
B.聚砜
C.聚丙烯
D.聚碳酸脂
参考答案:C
制备种植窝时骨床的温度不应超过()
A.42℃
B.47℃
C.37℃
D.45℃
E.25℃
What is the most important product-related factor to the transport cost?()
A.Linkages
B.Distance
C.Equipment
D.Time