这座城市改进了其垃圾处理系统。

The city has improved its waste ___disposal system.

妥善处理化学废料对安全至关重要。

Proper ___disposal of chemical waste is crucial for safety.

这家工厂因不当处理其副产品而面临罚款。

The factory faced fines for improper ___disposal of its byproducts.