列出最近的三个新闻标题和摘要。
1. "CDC Updates Mask Guidelines as Delta Variant Spreads" - The Centers for DiseaseControl and Prevention (CDC) has updated its guidelines on mask-wearing in indoor and publicsettings due to the spread of the Delta variant of COVID-19.

2. "Jeff Bezos Successfully Completes Blue Origin Space Flight" - Amazon founder Jeff Bezos and hiscrew successfully completed the first crewed flight of the Blue Origin spacecraft.

3. "Tokyo Olympics Begin Amid Pandemic Concerns" - The 2020 Tokyo Olympics officially kicked off, but concerns remain about the safety of the games as Japan continues to battle a surge in COVID-19 cases.