How to Use "unthinkable" with Example Sentences

1. Economic progress has propelled once unthinkable social changes .
2. That would have been unthinkable 20 years ago .
3. Some measures proposed to calm the markets seem unthinkable to many germans .
4. It was an act of personal trust that would have been unthinkable not long before .
5. And yet what is unthinkable for 98 percent of citizens is mandatory for the tiny minority .