According to some accounts which are impossible to verify, a major barracks or security headquarters has fallen to the opposition.

据一些无法证实的报道，一个主要的兵营或安全总部已经倒向反对派一边。

youdao

GCHQ, however, remains skeptical, stating that without the exact codebook, or full details of the encryption, it's impossible to verify any alleged solution.

ENGADGET: Alt-week 12.22.12: strange skulls, solar portraits and 17-minute code cracking

But like most of the information coming out of Tehran, it is impossible to verify her name -- Neda -- or the circumstances of her apparent death.

CNN: Iran media: Council rejects claims of voting irregularities

And since state ID such as a driver's license or birth certificate often vary by state or county, he adds, it's almost impossible for service employees to verify the authenticity.

CNN: Expert: Hijackers likely skilled with fake IDs