The actor's letters form the 'basis' of the biography. [=the biography is based on the actor's letters; the most important information in the biography comes from the actor's letters]
This principle forms the 'basis' [='base', 'foundation'] of the country's economic policies and will provide a firm 'basis' for future development.
These stories have very little 'basis' [='foundation'] in fact/reality. [=these stories are not based on or supported by facts/reality]
(..) -Actually, I minored in psychology. -Nice. -Okay, kiddo, fire me. -Ryan. Well, since she's gonna be doing this on a regular basis, don't you wanna know if she can fire somebody? -She's fired Ned. -My dog can fire Ned. Fire me. -You don't need to do this. (..)2009 Up in the Air
(..) I want you to stuff it all into that backpack. Now try to walk. It's kind of hard, isn't it? This is what we do to ourselves on a daily basis. We weigh ourselves down until we can't even move. And make no mistake, moving is living. Now, I'm gonna set that backpack on fire. (..)2009 Up in the Air