His tone was by turns angry and aggrieved.他的语气时而透着愤怒，时而流露出哀怨。We did the work by turns.我们轮流干这活.He gets cheerful and depressed by turns.他的情绪高一阵低一阵....

by turns的音标：...

轮流地，交替地，挨，更番...