stiff-plastic making

例句：

1. 1. The new car is made from stiff plastic.
   这辆新车是用硬塑料制成的。
2. 2. The company specializes in stiff-plastic making.
   该公司专门从事硬质塑料制造。
3. 3. The plastic material used in this product is stiff and strong.
   这种产品中使用的塑料材料是硬而坚固的。