【正确答案】 1、No sooner had you sent someone a private message    

【答案解析】本题考查no sooner... than... 结构。No sooner... than..., Hardly... when..., Scarcely... when... 构成的时间状语从句相当于as soon as之意，no sooner，hardly，scarcely位于句首时应采用倒装句，且前面主句用过去完成式，从句用过去式。