inquiry;  enquiry;  investigation;  (police) interview;  questioning (e.g. witness, suspect);  hearing
 pretext for not revealing something (e.g. actual reason for one's failure, vested interest, etc.)
 having good knowledge of a certain matter;  person who has good knowledge of a certain matter;  informed source
 economic condition;  economic circumstances;  financial situation
 internal (domestic) affairs
 traffic conditions (e.g. heavy traffic);  transportation situation (e.g. bad roads)
 social conditions;  social circumstances
 given the circumstances;  such being the case
 circumstances of the office
 clausula rebus sic stantibus (legal principle that agreements become non-binding if there is a major, unforeseeable change of circumstances)