1) Olympics, NBC. Women’s gymnastics is back, with Simone Biles (shown here) and other favorites. The team event will be shown early evening (7-9:30 p.m.), then concludes Tuesday. In the afternoon (12:15-6 p.m.), NBC plans to show swimming, surfing and diving, plus a men’s basketball game with the U.S. and France and the finals for men’s street skateboarding. Later at night (9:30-11:30 p.m.), it has swimming and skateboarding. There’s much more on cable and on the Peacock streaming service.
2) “Professor T,” 10 p.m., PBS. The first two episodes were so-so, burdened by its stoic/stony crimesolver. But now we get a hostage story, tangled enough to offer real promise: It’s possile that this time he’ll get something wrong, providing a hint of humanity. That follows an excellent “Unforgotten” hour at 9 on PBS … on a night when cable has pivotal episodes of “Kevin Can (bleep) Himself” (9 p.m., AMC) and a terrific “Black Monday” (10 p.m., Showtime.
3) “Celebrity Family Feud,” 8 p.m., ABC. Imagine Pee-Wee Herman facing a pack of wrestlers. That’s roughly what you get in the second half-hour: Paul Reubens (the Pee-Wee creator) and friends (including Drew Carey) face David Arquette and three wrestlers, including Jack “Jungle Boy” Perry, the son of the late “90210” star, Luke Perry. The first half-hour has teams led by Nev Schulman of “Catfish” and country star Jimmie Allen.
4) “Dead Pixels,” 9:30 p.m., CW. Last season, these videogame zealots finally conquered their favorite game. In last week’s season-opener, the sequel finally arrived … and was an instant disappointment. Still, they obsess; tonight Nicky uses all of his real money to buy video “treasures”; Meg sheds any hints of a real life. This lacks some of the charm of the first season, but is still OK. It follows the quiet wit of “Wellington Paranormal,” which tonight confronts a fierce shewolf.
5) “Where Have All the Theme Songs Gone?” 8 p.m., CNN, rerunning at 11. From “Gilligan” and “Brady Bunch” to “Cheers” and “Friends,” TV shows used to have bouncy theme songs. Now those are scarce; Don Lemon looks at the past … leading into a “History of the Sitcom” hour (9 pm. and midnight) that views workplace comedies.