跑得快是天生的吗？后天努力有没有用？一起来看看跑步的科学原理，你就明白了。 Photo/Pexels Usain Bolt, the world's faste

周一晚些时候，国家卫生委员会宣布将对新型冠状病毒进行重新分类，从1月8日起，将其从“新型冠状病毒肺炎”改为“新型冠状病毒感染”，同时根据国家传染病防治法，将该病的管理从A类降为B类，这就是新的调整意味着什么。问：降级管理的法律程序是什么？之后可能会出现什么风险？还有啊

Shanghai, China's economic hub with a population of more than 24.87 million, is all geared up to deal with a flare-up of COVID-19 infections

A special thought...—by Laine ParsonsSometimes it's not enough just to have you in my life; there are times when I need more of you than you give — more attention, more understanding, maybe even a little more of your time. Please understa