adj.非合金的,不掺杂的,纯粹的,真正的
At first blush , land is seen as a fixed or unalterable resource.
乍一看土地是一种固定的,或者说是不可改变的资源.
The general trend of history is unalterable.
历史发展的总趋势是不可改变的.
the unalterable laws of the universe
不可改变的宇宙法则