_,there was no mistaking that she was displwased.

adj./n./adv. +as +主语+谓语{尽管...}是as（或though）的倒装结构
具体如下：
当连词as 表示“虽然、尽管”引导让步状语从句时,句子要倒装,as 相当于though,可以替换.如：
Small as/though the atom is, we can smash it. 尽管原子很小,我们可以击碎它.
Tired as/though he was, he went on working. (=Although he was very tired, he went on working.) 虽然他很累,他还是接着工作.
Cold as/though it was, we went out. 虽然天气冷,我们还是出去了.
Child as/though she is, she knows a great deal. 她虽然是个孩子,但她懂得很多.
Teacher as he is, he knows little about teaching. 尽管他是个老师,但不懂什么教学.
Pilots as he claims he is, no one has ever seen him fly a plane. 尽管他声称是个飞行员,但谁也没见过他非飞机.
注意后四句是可数名词单数作表语并提前,习惯上不用冠词.