Not quite You would have to use a determiner prior to 'American landscape'. - :) "The American political landscape has been changing" (grammatical) - ): "American political landscape has been changing" (not grammatical) - :) "An American landscape, the political landscape, has been changing" (grammatical) - ): "American landscape, the political landscape, has been changing" (not grammatical) This holds unless you with to turn "American Landscape" into a proper noun of some sort. For example: "My startup is called 'American Landscape'. American Landscape is a company that focuses on evaluating the political landscape of America." This sentence is grammatical, but here 'American Landscape' is a proper noun referring to the name of a company, so different rules apply to it (we don't typically need determiners to be placed prior to proper nouns in English). Cheers

ladscape works for the view and beauty of the land yes. However note - situation and landscape arent really related so it depends what meaning you are actually trying to convey in your sentence.

Yes, you can use it in this context. Another word could be society is changing.