The police said they would not give up looking into other possibilities they find out what happened.
A. as
B. while
C. until
D. although
网友回答
A. as
B. while
(答案→)C. until
D. although
解析：考察连词。该句为not ……until……结构，直到……才……
句意为警察说他们不会放弃调查其他的可能性，直到他们发现到底发生了什么。