the jury is (still) out idiom
C2 （答案或观点）尚不明确，悬而未决
If the jury is (still) out on a subject, people do not yet know the answer or have not yet decided if it is good or bad.
The jury's still out on the safety of irradiated food. 人们对辐射处理过的食品是否安全尚不清楚。