In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

How do you know that the main topic of discussion is not overall considered high power?, Context: LEDs have also been used as a medium-quality voltage reference in electronic circuits. The forward voltage drop (e.g. about 1.7 V for a normal red LED) can be used instead of a Zener diode in low-voltage regulators. Red LEDs have the flattest I/V curve above the knee. Nitride-based LEDs have a fairly steep I/V curve and are useless for this purpose. Although LED forward voltage is far more current-dependent than a Zener diode, Zener diodes with breakdown voltages below 3 V are not widely available.
LEDs have also been used as a medium-quality voltage

What is sometimes combined with an RPG tube to keep from harming the user?, Context: Rocket-propelled grenades can be—and often are—used against hovering helicopters (e.g., by Somali militiamen during the Battle of Mogadishu (1993)). Firing an RPG at steep angles poses a danger to the user, because the backblast from firing reflects off the ground. In Somalia, militia members sometimes welded a steel plate in the exhaust end of an RPG's tube to deflect pressure away from the shooter when shooting up at US helicopters. RPGs are used in this role only when more effective weapons are not available.
a steel plate in the exhaust end

Who had the first American Idol showing?, Context: The first season of American Idol debuted as a summer replacement show in June 2002 on the Fox network. It was co-hosted by Ryan Seacrest and Brian Dunkleman.

Fox