我们设想，教员站在讲堂上，让投影大屏幕上文字段落被扩音器按照英文原文“大声朗读”出来，而且可以随意切换，停顿，或重复。此举不是机器不能，而是我们自会不会问题。
进入移动互联新时代，微积分教学要跟上新时代，脑袋与眼光要“活络”一些，死脑筋不行了。
袁萌 陈启清 8月13日
附：以下文章，值得一阅。
Make Edge browser read aloud eBook, PDF or Web page in Windows 10
It’s not surprising to see a collection of browsers running on our PCs and other mobile devices. Most of us use them for reading e-books. The latest build of Windows 10 features a native ebook store that allows you to purchase your favorite e-books. Besides, this, it also offers an immersing reading experience by allowing you to have your web page, PDF or eBooks read aloud by Mirosoft Edge browser.
All you need to do is fire up Edge, open an eBook, press the “Read aloud” button located at the top-right corner of the browser, sit back, relax and listen to your favorite eBook being read out to you.
Under Voices there are a limited number of accents to choose from in English including US, UK, etc. Each of these accents also has an enhanced quality version. For the default US version, the difference between the default and enhanced quality is pretty subtle.
When enabled, the feature will let you see the only headline, text, and any pictures that are vital to the article. You can even change the background color (背景色for reading in the dark!) and font size within reading view.
Let’s see how to have your book read aloud in Windows 10.
Launch Edge browser from your Start menu, desktop, or taskbar and hit the ‘Hub’ button. It is visible as three horizontal lines stacked atop each other and is acts as a central repository where Microsoft Edge keeps the things you collect on the web. You can select Hub to view your favorites, reading list, browsing history, and current downloads also.
Next, click the Books button. It looks like three books in a row. Select a book. Then, click the Read aloud button. Its icon is visible as a book with a speaker attached to it. When you confirm the action, a voice will immediately start reading the text aloud.
There are other buttons present that enable a user to control or manage the audio. For instance, you can pause, play or switch to the earlier, or next paragraph.（对教员最有用！）
If you are away to attend something important just hit the ‘Pause’ button and resume reading once you are back.
Also, if you just want to go rapidly over something, without noticing details simply do a cursory reading by clicking the forward button to skip a line of the article.
If you would like to adjust the speed settings for the reading, click the ‘Voice’ settings button. ??
Thereafter, simply hit and drag the bar on the slider to change the reader’s speed.
To restore settings to original, hit the dropdown arrow beneath Voice. Click a voice and hit the blue X near the top-right corner to return to restore original settings for the reading.
In Windows 10 v1709, you can now also access this feature via Edge right-click context menu. Using this feature you can make EDge read aloud a webpage or a PDF file as well.
You can also pause or stop the reading.
I am sure that some of you will find this feature very useful.
（……以下省略）