alternate [ɔ:lˈtɜ:nət]

以下由轻松背单词网站提供

adj.交替的，间隔的；v.（使）轮流　　

to happen or exist one after the other repeatedly

He and I clean our room on alternate days. 我和他隔日轮流打扫我们的房间。
That was a week of alternate rain and sunshine. 那是晴雨天交替的一周。