名词

1. 活页夹
A binder is a hard cover with metal rings inside, which is used to hold loose pieces of paper.

1. something used to tie or bind

Synonym: ligature

2. holds loose papers or magazines

Synonym: ring-binder

3. a machine that cuts grain and binds it in sheaves

Synonym: reaper binder

4. something used to bind separate particles together or facilitate adhesion to a surface