1. from time to time 不时，有时

eg. She sat silently,flinging the odd word into the conversation from time to time.
她静静地坐着听谈话，不时插进一两句。

eg. Sometimes going over the top is good, if you can let yourself go from time to time, people will notice.
有时挣脱束缚是好的，如果你能够让自己一次又一次地挣脱束缚，人们会注意到你的。

2. There is no doubt that 毫无疑问的是……

eg. There is no doubt that this policy will be a golden opportunity for all business sectors.
毫无疑问，这项政策对所有的商业部门来说将是一个黄金机会。

eg. It is a reasonable question, because there is no doubt that Brazil's economy is overheating.
这是一个合理的问题，因为毫无疑问，巴西的经济已处于过热状态。