on request

英文解釋：

副詞 on request:

1. on the occasion of a request
   同義詞：for the asking

相關句子：

1. Buses stop here on request.
   有人要求時，公共汽車在此停車。
2. Catalogues are available on request.
   備有目錄供索取。
3. Full details will be sent on request.
   有詳細材料備索。