a big ask
要求过于苛刻或困难，难以实现
口语·表示要求过高或难以实现
英文释义
something that is difficult or demanding to achieve or obtain
例句
Asking him to finish the project in one day is a big ask, but he might pull it off.
典故来源
源自20世纪英语口语，强调请求或任务难度极大。