principal level是什么意思 principal level怎么读
principal level的用法和样例
- Production of glass fiber gypsum products, glass fiber is the Principal and senior gypsum powder as main raw material, together with the cast from high-performance additives.
公司生产的玻璃纤维石膏系列产品，是以特等玻璃纤维和高级石膏粉为主要原料，配以高性能添加剂浇铸而成。
展开更多
