请在下面的括号里填上恰当的表示人体器官名称的词

犯罪分子的（ 头脑）可真狡猾,我们真得小心。                                                                                                   
2。把（ 心）放宽些,多往将来想。                                                                                                                         
3。小明和王刚朝夕相处,真是情同（ 手足）。                                                                                                                 
  4。南京是蒋介石的（心脏 ）。