1. It is unthinkable to keep children so young away from their parents for so long, and with so little support.

2. Both biological and technical advances can provide treatments that were unthinkable only a few years ago.

3. They know he would not have committed this unthinkable, tragic occurrence without being sick.

4. The once unthinkable is about to become reality.

5. With the advancement of modern science, we now enjoy research options that were unthinkable a few decades ago.

6. By then, XP had been equipped with a software firewall, an almost unthinkable feature for an OS three years eariler.

7. Well, as novel as the Internet still is, we have nevertheless managed to think about the unthinkable before.