11.   Rap music remains a fertile source of slang, for both black and white students, Eble said.

12.   The British Isles make a fertile source of choice films.

13.   The high-tech region near her San Francisco district is a fertile source of campaign contributions.

14.   The urban environment is also becoming a fertile source for younger artists.

15.   The growth in high-tech companies has turned the industry into a fertile source of campaign contributions.

16.   Theater fertile source of talent, with stage directors Stephen Daldry, Nicholas Hytner, Roger Michell, Hettie Macdonald and Sean Mathias heading toward cinema.