请问now and then和every now and then again意思分别是什么?

请问now and then和every now and then again意思分别是什么? now and again和now and then意思相同吗? now and then和every now and then的意思完全相同吗? now and then 和 now and again 的区别? every now and then是什么意思? every now and then 还是 now and then?表示不时? now and then 与 every now and then 的区别是什么? every now and then和now and then 有什么区别? Every now and then和once in a while now and then 作文,Then and now now and then 等于then吗?