A、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-family: ">单片拱肋<span style="mso-spacerun: yes"></span></span>
B、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-family: ">垂直布置的双片拱肋</span>
C、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-family: ">提篮拱（内倾布置的双片拱肋）</span>
D、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-family: ">蝴蝶拱（外倾布置的双片拱肋）</span>