政府在减少污染方面取得了具体成就。

The government has made ___concrete achievements in reducing pollution.

在物理学中，我们研究抽象概念和具体物体。

In physics, we study both abstract concepts and ___concrete objects.

为了使学习有意义，它必须与具体情况相关联。

To make learning meaningful, it must be related to ___concrete situations.