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]
(..) KOOTHRAPPALI (high-pitched): Yes. Will you please tell me where we're going? Sorry, you're on a need-to-know basis. I'm driving the car. I need to know. Right. So where are we going? No, I meant turn right, (..)2016 TvShow: The Big Bang Theory Title: The Solder Excursion Diversion Season: 9 Episode 19