Problem: Light-emitting diode:

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.

What LED has the least flattest I/V curve above the knee?
---
A: unanswerable

Problem: Materialism:

Despite the large number of philosophical schools and subtle nuances between many, all philosophies are said to fall into one of two primary categories, which are defined in contrast to each other: Idealism, and materialism.[a] The basic proposition of these two categories pertains to the nature of reality, and the primary distinction between them is the way they answer two fundamental questions: "what does reality consist of?" and "how does it originate?" To idealists, spirit or mind or the objects of mind (ideas) are primary, and matter secondary. To materialists, matter is primary, and mind or spirit or ideas are secondary, the product of matter acting upon matter.

A materialist considers what as the most important?
---
A: matter

Problem: Hindu philosophy:

Dvaitadvaita was proposed by Nimbarka, a 13th-century Vaishnava Philosopher from the Andhra region. According to this philosophy there are three categories of existence: Brahman, soul, and matter. Soul and matter are different from Brahman in that they have attributes and capacities different from Brahman. Brahman exists independently, while soul and matter are dependent. Thus soul and matter have an existence that is separate yet dependent. Further, Brahman is a controller, the soul is the enjoyer, and matter the thing enjoyed. Also, the highest object of worship is Krishna and his consort Radha, attended by thousands of gopis; of the Vrindavan; and devotion consists in self-surrender.

What controls Brahman?
---
A: unanswerable

Problem: British Isles:

The earliest known references to the islands as a group appeared in the writings of sea-farers from the ancient Greek colony of Massalia. The original records have been lost; however, later writings, e.g. Avienus's Ora maritima, that quoted from the Massaliote Periplus (6th century BC) and from Pytheas's On the Ocean (circa 325320 BC) have survived. In the 1st century BC, Diodorus Siculus has Prettanike nesos, "the British Island", and Prettanoi, "the Britons". Strabo used (Brettanike), and Marcian of Heraclea, in his Periplus maris exteri, used (the Prettanic Isles) to refer to the islands. Historians today, though not in absolute agreement, largely agree that these Greek and Latin names were probably drawn from native Celtic-language names for the archipelago. Along these lines, the inhabitants of the islands were called the (Priteni or Pretani). The shift from the "P" of Pretannia to the "B" of Britannia by the Romans occurred during the time of Julius Caesar.

Although the original records have since been found, later writings that quoted from what are lost?
---
A:
unanswerable