Delegates in Spain hit a major stumbling block Tuesday when the African group pulled out of some climate talks, saying rich nations are not doing enough to tackle climate change.

VOA: standard.2009.11.04

Milton's own faculty of memory - this is the idea that I'm going to be floating here - seems to provide something like, or pose a stumbling block or an obstacle for, his attempt to write an original, divinely inspired poem.

在这里我想说,弥尔顿自己的记忆系统,似乎想提供某种东西，或者想在他写出一部原创的，伟大的诗作的尝试上设置一个障碍。

耶鲁公开课 - 弥尔顿课程节选

Mohammed Said Idries, of the Al Ahram Center for Strategic Studies, says that there are many reasons why the electoral law remains stalled in the Iraqi parliament, but that the quarrel about the identity Kirkuk is one key stumbling block.

VOA: standard.2009.10.26