A、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-bidi-font-family: " times="" new="" roman";="" mso-font-kerning:="" 1.0pt;="" mso-ansi-language:="" en-us;="" mso-fareast-language:="" zh-cn;="" mso-bidi-language:="" ar-sa"="">弯矩作用</span>
B、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-bidi-font-family: " times="" new="" roman";="" mso-font-kerning:="" 1.0pt;="" mso-ansi-language:="" en-us;="" mso-fareast-language:="" zh-cn;="" mso-bidi-language:="" ar-sa"="">弯矩和剪力共同作用</span>
C、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-bidi-font-family: " times="" new="" roman";="" mso-font-kerning:="" 1.0pt;="" mso-ansi-language:="" en-us;="" mso-fareast-language:="" zh-cn;="" mso-bidi-language:="" ar-sa"="">拉力作用</span>
D、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-bidi-font-family: " times="" new="" roman";="" mso-font-kerning:="" 1.0pt;="" mso-ansi-language:="" en-us;="" mso-fareast-language:="" zh-cn;="" mso-bidi-language:="" ar-sa"="">剪力作用</span>