open-ended
adjective uk/ˌəʊ.pənˈen.dɪd/ us/ˌoʊ.pənˈen.dɪd/
无结论的;无限制的;未预作安排的
An open-ended activity or situation does not have a planned ending, so it may develop in several ways.
We are not willing to enter into open-ended discussions. 我们不想无休止地讨论下去。