在公文的开头，通过情况的介绍、问题的提出或意义的明确，使受文者了解行文的缘由，引起对文件内容的重视，这种写法是（    ）

<span style、"font-family: 宋体; font-size: 10.5pt; 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;">根据式 </span>

<span style、"font-family: 宋体; font-size: 10.5pt; 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;">混合式</span>

<span style、"font-family: 宋体; font-size: 10.5pt; 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;">目的式</span>

<span style、"font-family: 宋体; font-size: 10.5pt; 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;">缘由式 </span>