“时而”怎么读？

她情绪多变，时而咄咄逼人，时而又显得温柔平和或乐于合作。Her aggressive moods alternated with gentle or more co-operative states.他的语气时而透着愤怒，时而流露出哀怨。His tone was by turns angry and aggrieved.他因不守时而受到处罚。He was penalized for bad timekeeping....

“时而”的英语可以翻译为：from time to time，sometimes，now ... now ...，sometimes ... sometimes ...，ever and agah ...