比如，我们不知道伊朗是否在未遭披露的地方进行秘密的活动，伊朗何时能研发出粗糙的核武器，据估计是在几个月到几年之间。
For example, we do not know whether Iran is conducting secret activities at undisclosed sites, or when Iran could develop a crude nuclear weapon, with estimates ranging from several months to several years.