The study of preparation of maleated rosins and their application as paper size was started in China in 1974.
我国对马来松香的研制及其用作造纸施胶剂进行了十多年的研究。
3
Our company , a musical instrument manufacturer with self-run right of import and export , mainly produce violins , violas , cellos , double-basses , rosins etc by hand over 20 years .