1·In many cases, resizing operations can proceed smoothly; however, numerous stumbling blocks can cause problems for the unwary, or even for those who take adequate precautions.
很多情况下，调整操作一般都很顺利，然而，许多障碍都是粗心大意引起的，甚至对那些已经做了充分准备的人也不能避免。
2·The 17-year-old competition has helped identify common stumbling blocks in protein-shape prediction and focus research efforts, its founders have said.
比赛发起者说，历时17年的比赛已经帮助找到了影响蛋白结构预测的常见障碍，并且还有集思广益的效果。
3·The question of disarmament proved a major stumbling block to agreement.
裁军问题是达成协议的主要障碍。
4·Barack Obama's announcement of an Afghan "surge" is his frantic bid to rescue what promises to be a stumbling re-election campaign that must start in 2011.
对于阿富汗的“增兵公告”，奥巴马宣告他会努力尽快拯救成为那些有希望障碍2011年开始的重选运动的因素。
5·Talk about stumbling blocks. About confidentiality. How do you close the relationship if it doesn't work out?
共同讨论一下双方将面临的障碍、保密性问题，以及万一没能达到预期效果，如何终止双方的关系等？