in the dark
1．with no light黑暗
Don't leave the child alone in the dark；he'll be afraid．不要把孩子单独留在黑暗中，他会害怕的。
I hit my head against the door in the dark．黑暗中我的头撞在了门上。
2．in ignorance不知道；隐瞒
John was in the dark about the job he was being sent to．约翰对于指派他做的工作一无所知。
Tax payers don't like being kept in the dark about the government's intentions．纳税人不希望对政府的打算一无所知。
I am still kept in the dark about the matter．对这事我仍然一无所知。
It is not necessary to keep it in the dark．这件事没有必要保密。