A rare documentary with alternating moments of pathos, insight and inadvertent comedy, “Please Vote for Me” on “Independent Lens” (9 p.m., PBS, check local listings) offers a rare glimpse at a modern China coming to grips with democracy. “Vote” follows a class of 8-year-old Chinese students asked to elect a school monitor from a slate of three candidates chosen by the teachers.

The kids in “Please Vote” provide a great vantage point to watch a society in transition. Few of them understand the notion of voting or democracy. Their school songs and marching slogans still reflect an authoritarian culture and a reverence for the ruling Communist Party.

Yet the scenes shot at the students’ homes indicate a growing prosperity and show apartments filled with televisions and conveniences that would not be out of place in the United States.

What makes “Please Vote” is its remarkably intimate depiction of the candidates, their hovering stage parents and the devious lengths one would-be monitor will go to sabotage the campaigns of his rivals.

Like the school votes in big-screen comedies “Election” and “Napoleon Dynamite,” this one includes a talent show, strange and sneaky behavior and competition that can only be considered cutthroat.

¢ “Dirty Jobs” (8 p.m., Discovery) travels to San Francisco to celebrate 150 filthy temp assignments and to look forward to many more. The 150th task involves Mike’s stint as a yak farmer in Kalispell, Mont.

The two-hour show will offer a wealth of “Dirty” clips; a glance at the boots, T-shirts and uniforms that Mike has soiled on his sojourn; a pig roast; a fireworks display; and a performance of the song “Dirty Dirty.”

¢ CNN will spend four hours over the next two nights on “Planet in Peril” (8 p.m., CNN). Correspondents Anderson Cooper, Jeff Corwin and Dr. Sanjay Gupta offer reports from four continents and 13 countries on four main concerns: climate change, deforestation, species loss and overpopulation.

¢ Horror, fantasy and sci-fi films get their due at the Scream 2007 Awards (9 p.m., Spike).

Tonight’s other highlights

¢ An organic farmer’s death seems anything but natural on “Bones” (7 p.m., Fox).

¢ A new patient believes she’s a ghost whisperer on “House” (8 p.m., Fox).

¢ Sam gets a copy of his parents’ deal with the devil on “Reaper” (8 p.m., CW).

¢ “Frontline” (8 p.m., PBS, check local listings) presents “Showdown with Iran,” a survey of the ups and downs of U.S. relations with Tehran since Sept. 11, 2001.

¢ Alex feels his power slipping on “Cane” (9 p.m., CBS).

¢ A stabbing victim appears to be an idealistic teacher on “Law & Order: Special Victims Unit” (9 p.m., NBC).

¢ A woman (Mare Winningham) consults Alan about revenge on “Boston Legal” (9 p.m., ABC).

¢ The complicated legal mystery “Damages” (9 p.m., FX), starring Glenn Close, Ted Danson and Rose Byrne, concludes its first season.

¢ “REAL Sports with Bryant Gumbel” (9 p.m., HBO) looks at the plight of athletes in Iraq, where sports stars have been kidnapped, tortured and killed by insurgents.

Cult choice

A war hero schemes the death of his lover’s husband in the 1958 French-language film-noir mystery “Elevator to the Gallows” (7 p.m., TCM), directed by Louis Malle and featuring a haunting and very cool score by Miles Davis.