envelope conformation

例句：

1. 1.The envelope's shape affects how the mail is delivered.
   信封的形状影响邮件的投递方式。
2. 2. The envelope's construction determines its durability.
   信封的结构决定了它的耐用性。
3. 3. The envelope's design is a crucial factor in the overall aesthetic of a package.
   信封的设计是包裹整体美学的关键因素。