Bill Gates: 过去几年的几次巨大的全球性挫折让许多人灰心丧气，并怀疑世界是否注定会变得更糟。

原推：Several huge global setbacks over the past few years have left many people discouraged and wondering whether the world is destined to get worse.
https://twitter.com/BillGates/status/1547235377773088768