In the Kremlin, America's Europe-based missile defense system, which Russia has fiercely opposed, seems to be a stumbling block.
"Our analysis is, there should be nothing that at this point would appear to be a stumbling block.
How much of the cost should be picked up by industry is likely to be a stumbling block.
However, a spokesman for the prosecutors handling the case said last week that Germany's 30-year statute of limitations may prove to be a stumbling block.
This was a darker version, featuring Carroll himself as a character; once again, the structure of the story proved to be a stumbling block.
Price, said Michael Gartenberg, a senior analyst with research firm Gartner, could be a stumbling block.
For example, [agreeing to] the 5-year cycle of commitment reviews could be a stumbling block.
The 25-year-old is a player United boss David Moyes admires but Chelsea's valuation, believed to be more than £35m, could be a stumbling block.
If you're not in a standard, tenure-track faculty position, "the support of a qualified institution" may be a stumbling block.
If you are at an educational institution, especially teaching young children, I think the multi-step curing process could be a stumbling block.
But bruised egos also seem to be a stumbling block.
