正确理解词语 解释下列词语。
①正襟危坐:____________________________________________________________________
②诚惶诚恐:____________________________________________________________________
③鹤立鸡群:____________________________________________________________________
④藏污纳垢:____________________________________________________________________
⑤颔首低眉:____________________________________________________________________
⑥粗制滥造:____________________________________________________________________
⑦麻木不仁:____________________________________________________________________