Different grades of crystal polystyrene molding pellets range from 150,000 to 350,000 weight average molecular weight.不同牌号的结晶聚苯乙烯模塑粒料平均分子量范围从150,000-350,000.What factors does he take into consideration in determining the...
This teakettle will whistle when the water boils.这茶壶在水开时会发出嘘嘘声.The iron teakettle was hissing splendidly over live coals.煤火烧得正旺,上面的铁茶壶嘶嘶地响个不停。The iron teakettle was hissing splendidly over live coals...煤火烧得正旺,上面的铁茶壶嘶嘶地响个...