1) “Call Me Kat,” 9:30 p.m., Fox. Popping into what will be its timeslot in the fall, this likable show reruns its season-opener. It’s a good one that give Mayim Bialik (shown here), starring as Kat, a chance to reunite with her old “Blossom” castmates. Joey Lawrence, Jenna von Oy and a self-deprecating Michael Stoyanov play themselves, in some goofy bits at the start of the episode.
2) “Young Sheldon” and “Ghosts,” 8 and 8:30 p.m., CBS. Here’s the new normal for CBS on Thursdays, shrinking from four comedies to two. “United States of Al” and “B Positive” are gone; the 9 p.m. hour goes to “Big Brother” now and to a light drama this fall. Now, at least, the two top comedies are side-by-side. Tonight, Ming-Na Wen is a scientist, clashing with Sheldon. Then the ghosts help spy on disapproving neighbors.
3) “The Old Man” (FX) or “Good Trouble” (Freeform), both 10 p.m. Two dramas collide. The much-praised “Old Man” is a week from its season-finale; Chase and Zoe (Jeff Bridges and Amy Brenneman) head into dangerous turf, while their pursuer (John Lithgow) ends one partnership and starts another. “Good Trouble” returned last week, for the second half of its season. Luca – the homeless man Joaquin is writing about — moves in, but doesn’t feel at home.
4) “Top Gear” season-opener, 10 p.m., BBC America. These three British blokes announce they’ll try “a corner of the world that just loves wacky racing.” That’s Florida, where they clunk along in a 35-foot RV, looking for alligators and odd race tracks. They see 1,000-hp motors in swamp buggies (able to reach 80 mph) and in spiffed-up Chevys (reportedly able to hit 150-mph in a quarter-mile). The result is very noisy and fairly entertaining.
5) ALSO: “Welcome to Flatch,” a drolly clever show, settles into Fox’s 9 p.m. slot, where it will be this fall; tonight, the cousins have new schemes – treasure maps, a hip hop dance school – to make money. And cable reaches shark overload. While “Shark Fest” continues on National Geographic (including “When Sharks Attack” at 8), Turner Classic Movies counters with “Tiger Shark” (1932) and “The Sharkfighters” (1956), at 8 and 9:30 p.m. ET.