Ofallthematerialsprovidedbynatureformantouseasamaterialofconstruction,naturalrubberisunique.Thecharacteristicofhighreversibleextensibilityfascinatestheenquiringmind.AstheyearshavepassedsinceitsintroductiontotheEasternHemispherebyColumbusandhisfellowexplor (共 9350 字) [阅读本文] >>