The last decade has witnessed a serious rise in the levels of racism and hostility to Black and ethnic groups.过去十年里，对黑人及少数族裔的种族歧视和敌对行为变得日益猖獗。Our dogs have never shown aggression towards other dogs.我们的狗从不对其他狗表现出敌对行为 。Any hostilities could result in retaliation and further embroil U.N. troops in fighting.任何敌对行为都可能导致报复，进而把联合国部队卷入冲突。