在求一个正则表达式~~
<SPAN   style= "FONT-SIZE:   12pt;   FONT-FAMILY:   宋体 "> 补出下列句子中省略的主语： <BR> <SPAN   lang=EN-US   style= "FONT-SIZE:   12pt;   FONT-FAMILY:   宋体;   mso-font-kerning:   1.0pt;   mso-bidi-font-family:   'Times   New   Roman ';   mso-ansi-language:   EN-US;   mso-fareast-language:   ZH-CN;   mso-bidi-language:   AR-SA "> <BR> 1 </SPAN> <SPAN   style= "FONT-SIZE:   12pt;   FONT-FAMILY:   宋体;   mso-font-kerning:   1.0pt;   mso-bidi-font-family:   'Times   New   Roman ';   mso-ansi-language:   EN-US;   mso-fareast-language:   ZH-CN;   mso-bidi-language:   AR-SA "> 、  
<DIV   id=fill_empty1   style= "DISPLAY:   inline;   FONT-SIZE:   12px;   WIDTH:   70px;   BORDER-BOTTOM:   #3300ff   1px   solid;   FONT-FAMILY:   宋体;   HEIGHT:   15px "   ms_positioning= "FlowLayout "   ;align= "left "> <SPAN   style= "FONT-SIZE:   12pt;   FONT-FAMILY:   宋体;   mso-font-kerning:   1.0pt;   mso-bidi-font-family:   'Times   New   Roman ';   mso-ansi-language:   EN-US;   mso-fareast-language:   ZH-CN;   mso-bidi-language:   AR-SA "> 渔人 </SPAN> </DIV> <SPAN   style= "FONT-SIZE:   12pt;   FONT-FAMILY:   宋体;   mso-font-kerning:   1.0pt;   mso-bidi-font-family:   'Times   New   Roman ';   mso-ansi-language:   EN-US;   mso-fareast-language:   ZH-CN;   mso-bidi-language:   AR-SA "> 便舍船，从口入。  
<DIV   id=fill_empty2   style= "DISPLAY:   inline;   FONT-SIZE:   12px;   WIDTH:   70px;   BORDER-BOTTOM:   #3300ff   1px   solid;   FONT-FAMILY:   宋体;   HEIGHT:   15px "   ms_positioning= "FlowLayout "   ;align= "left "> <SPAN   style= "FONT-SIZE:   12pt;   FONT-FAMILY:   宋体;   mso-font-kerning:   1.0pt;   mso-bidi-font-family:   'Times   New   Roman ';   mso-ansi-language:   EN-US;   mso-fareast-language:   ZH-CN;   mso-bidi-language:   AR-SA "> 山洞 </SPAN> </DIV> <SPAN   style= "FONT-SIZE:   12pt;   FONT-FAMILY:   宋体;   mso-font-kerning:   1.0pt;   mso-bidi-font-family:   'Times   New   Roman ';   mso-ansi-language:   EN-US;   mso-fareast-language:   ZH-CN;   mso-bidi-language:   AR-SA "> 初极狭，才通人。 <BR> </SPAN> </SPAN> </SPAN> <SPAN   lang=EN-US> <?xml:namespace   prefix   =   o   ns   =   "urn:schemas-microsoft-com:office:office "   /> <o:p> <SPAN   lang=EN-US   style= "FONT-SIZE:   12pt;   FONT-FAMILY:   宋体;   mso-font-kerning:   1.0pt;   mso-bidi-font-family:   'Times   New   Roman ';   mso-ansi-language:   EN-US;   mso-fareast-language:   ZH-CN;   mso-bidi-language:   AR-SA "> <BR> 2 </SPAN> <SPAN   style= "FONT-SIZE:   12pt;   FONT-FAMILY:   宋体;   mso-font-kerning:   1.0pt;   mso-bidi-font-family:   'Times   New   Roman ';   mso-ansi-language:   EN-US;   mso-fareast-language:   ZH-CN;   mso-bidi-language:   AR-SA "> 、  
<DIV   id=fil