Human lifespan has doubled in the last 100 years. Some of the reasons are obvious but many are quite surprising. We discuss them with appropriate charts and graphs.
The Google Drive folder contains a PowerPoint file and a sub-folder with video files. Click on 
to open the content of the folder. Then do either of the following:
1) if you aren’t logged in to any Google account, click on the link near the top right that says “Download all”, or
2) if you are logged in to a Google account, at the top of the screen, locate the folder name (to the right of the “>” sign), right-click on the folder name and choose Download from the drop-down menu.
Google Drive will automatically download all contents in the folder as a ZIP file.
On your computer, extract the ZIP file to a folder of your choice. Open the PowerPoint and the embedded links to the video files will work. They cannot work while you are viewing the PowerPoint from the website.
