America's unsolved problems of poverty and racism美国尚未解决的贫困和种族歧视问题

The murder remains unsolved.谋杀案仍未侦破。

For unsolved crimes, the police can keep a case open as long as they like.对于未侦破的案件, 警方可一直不结案。

I shuddered when I thought of how many unsolved cases the police had on file.想到警方有多少存档的未破案件时, 我感到不寒而栗。