question: the sliding control makes it possible to vary the rotational speed.
Capitalize this past sentence correctly.
A: The sliding control makes it possible to vary the rotational speed.

question: the best solution for the high-tech diy'er
Capitalize this past sentence correctly.
A: The best solution for the high-tech DIY'er

question: free wifi is provided.
Capitalize this past sentence correctly.
A: Free WiFi is provided.