https://static01.nyt.com/images/2022/11/23/multimedia/CN-23walmart-shooting-carousel-3-1-4c2f-copy/23walmart-shooting-carousel-3-1-4c2f-mediumThreeByTwo440.jpg简报：美国10日内发生三起大规模枪击案；美官员称新冠威胁在今冬有所下降