今天我们要学的词是 head off. Head off 有防止，避免的意思。The Food and Drug Administration announced a new proposal to try to head off shortages of crucial medications. 美国食品和药物管理局宣布了一项新提案，努力防止重要药物出现短缺。Russia's Parliament passed a bill imposing prison terms of up to six years on Russians who take part in conflicts abroad, trying to head off potential security threats ahead of the Winter Olympics in Sochi. 俄罗斯议会通过法案，对在国外参加暴力冲突的俄罗斯人判处高达六年的刑期，希望借此防止索契冬季奥运会前出现安全隐患。好的，今天我们学习的词是 head off, head off, head off.
