城市的垃圾收集服务每周运行两次。

The city's garbage ___collection service operates twice a week.

我们需要一个更高效的组织来进行废物收集。

We need a more efficient organization for the ___collection of waste.

从家庭收集可回收物对可持续发展至关重要。

The ___collection of recyclables from households is crucial for sustainability.