甲、乙两个科室各有4名职员,且都是男女各半。现从两个科室中选出4人参加培训,要求女职员比重不得低于一半,且每个科室至少选1人。问有多少种不同的选法?( )
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
免费的网站请分享给朋友吧