Totally synthetic materials can serve as valuable lead structures and are frequently needed as starting materials.

猜你喜欢

• If a brand has a large number of suppliers and sufficient storage of raw materials，（）should not be set as the priority in determ
• According to the making materials, musical instruments were divided into metal, stone, earth, leather, silk, wood, pao and bambo
• The reason why most plastic packaging materials don’t get recycled is that many people don’t realize their side-effects.
• In ancient times, only materials available in the nature were used to form packages.
• When we think about supporting materials and organizational methods, we're thinking about the （） of the speech.