Certainly people do not seem less interested in success and its signs now than formerly. Summer homes, European travel, BMWs—the locations, place names and name brands may change, but such items do not seem less in demand today than a decade or two years ago.

翻译: 当然，现在人们对成功及其标志的兴趣似乎不亚于从前，避暑别墅、欧洲旅行、宝马车——地点、地名和品牌或许会有变化，但现在对这些东西的渴求似乎并不亚于一二十年前。

疑问: 请问句中，do not seem 是作谓语还是作系动词？谢谢!