1.   His criminal history was unknown to the Kanka family.

2.   His plan of the moment was unknown to the Federals, but they had a pretty good idea of his general intentions.

3.   Most of the stars in the movie are unknown to US audiences.

4.   Only five years ago, Mrs Shephard - the new Employment Secretary - was unknown to national politics.

5.   Radon exposure is the hottest issue among radiation scientists today - but it remains almost entirely unknown to the public.

6.   The Internet has opened up a Marketplace where sellers and buyers are virtually unknown to each other.

7.   They had their own ideas about who committed all the robberies in the area, and Oliver was unknown to them.

8.   I could not understand how someone with so many awards could be unknown to me.

9.   All three individuals resided abroad and their precise whereabouts were unknown to US officials.

10.   This makes it highly unlikely that any further operations would be unknown to us.