用作表语
▲S+be+～
Is smoking permissible in the theatre?在剧院里允许吸烟吗?
▲It is/was+～+to-v
I understood that it was permissible to ask a question.我想是准许提问题的吧。

［派生词］ permissibility n. 允许，许可‖permissibleness n. 允许，许可‖permissibly adv. 允许地，许可地