A smart TV connected to the internet can deliver on-demand and catch-up TV services.联网的智能电视可提供随选和补看服务。They will sell a voice recognition product as an add-on, on-demand service for their users.他们会将一个语音识别系统作为附加的随选服务提供给用户。My cable company offers on-demand service/movies.我的有线电视公司提供点播服务/电影点播。