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That's not a bad opening. I might change it to "Today we're going to talk about..." to make it more inclusive, but there's nothing wrong with being straightforward. Another version might be "Today ...
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#4: Attribution notice removed
Source: https://writers.stackexchange.com/a/6297 License name: CC BY-SA 3.0 License URL: https://creativecommons.org/licenses/by-sa/3.0/
#3: Attribution notice added
Source: https://writers.stackexchange.com/a/6297 License name: CC BY-SA 3.0 License URL: https://creativecommons.org/licenses/by-sa/3.0/