World News Roundup: 07/28

<p>Debate over the CDC's new mask guidance.&nbsp;Simone Biles will skip tomorrow's individual competition.&nbsp;Deadly TX chemical leak.&nbsp;CBS News Correspondent Steve Kathan has today's World News Roundup.</p><p>See Privacy Policy at <a href="https://art19.com/privacy" rel="noopener noreferrer" target="_blank">https://art19.com/privacy</a> and California Privacy Notice at <a href="https://art19.com/privacy#do-not-sell-my-info" rel="noopener noreferrer" target="_blank">https://art19.com/privacy#do-not-sell-my-info</a>.</p>