A fish out of water:

魚(yú)離開(kāi)了水 ×

十分不自在 √

例句：

She feels like a fish out of water among the celebrities.

在那些達(dá)官貴人中，她感到十分不自在。

Fish tale:

魚(yú)的故事 ×
謊言 √

例句：

Kelly is a master at the fish tale. She should be a politician [?p?l??t??n].

Kelly真是個(gè)謊話(huà)精，真應(yīng)該當(dāng)個(gè)政治家。

Be kept in the dark:

被隱藏在黑暗中 ×

被蒙在鼓里 √

例句：

We were kept completely in the dark about his plan to sell the company.  

對(duì)他計(jì)劃將公司出售一事，我們一直蒙在鼓里。