Problem: Please answer a question about the following article about Neolithic:
In southeast Europe agrarian societies first appeared in the 7th millennium BC, attested by one of the earliest farming sites of Europe, discovered in Vashtemi, southeastern Albania and dating back to 6,500 BC. Anthropomorphic figurines have been found in the Balkans from 6000 BC, and in Central Europe by c. 5800 BC (La Hoguette). Among the earliest cultural complexes of this area are the Sesklo culture in Thessaly, which later expanded in the Balkans giving rise to Starcevo-Koros (Cris), Linearbandkeramik, and Vinca. Through a combination of cultural diffusion and migration of peoples, the Neolithic traditions spread west and northwards to reach northwestern Europe by around 4500 BC. The Vinca culture may have created the earliest system of writing, the Vinca signs, though archaeologist Shan Winn believes they most likely represented pictograms and ideograms rather than a truly developed form of writing. The Cucuteni-Trypillian culture built enormous settlements in Romania, Moldova and Ukraine from 5300 to 2300 BC. The megalithic temple complexes of Ggantija on the Mediterranean island of Gozo (in the Maltese archipelago) and of Mnajdra (Malta) are notable for their gigantic Neolithic structures, the oldest of which date back to c. 3600 BC. The Hypogeum of al-Saflieni, Paola, Malta, is a subterranean structure excavated c. 2500 BC; originally a sanctuary, it became a necropolis, the only prehistoric underground temple in the world, and showing a degree of artistry in stone sculpture unique in prehistory to the Maltese islands. After 2500 BC, the Maltese Islands were depopulated for several decades until the arrival of a new influx of Bronze Age immigrants, a culture that cremated its dead and introduced smaller megalithic structures called dolmens to Malta. In most cases there are small chambers here, with the cover made of a large slab placed on upright stones. They are claimed to belong to a population certainly different from that which built the previous megalithic temples. It is presumed the population arrived from Sicily because of the similarity of Maltese dolmens to some small constructions found in the largest island of the Mediterranean sea.
What trend led to Neolithic traditions spreading to northwestern Europe by around 4500 BC?
A: cultural diffusion and migration of peoples
Problem: Please answer a question about the following article about Culture:
Other 19th-century critics, following Rousseau have accepted this differentiation between higher and lower culture, but have seen the refinement and sophistication of high culture as corrupting and unnatural developments that obscure and distort people's essential nature. These critics considered folk music (as produced by "the folk", i.e., rural, illiterate, peasants) to honestly express a natural way of life, while classical music seemed superficial and decadent. Equally, this view often portrayed indigenous peoples as "noble savages" living authentic and unblemished lives, uncomplicated and uncorrupted by the highly stratified capitalist systems of the West.
What type of music did critics associate with corrupt high culture?
A: folk music
Problem: Please answer a question about the following article about Antenna (radio):
Due to reciprocity (discussed above) the gain of an antenna used for transmitting must be proportional to its effective area when used for receiving. Consider an antenna with no loss, that is, one whose electrical efficiency is 100%. It can be shown that its effective area averaged over all directions must be equal to 2/4, the wavelength squared divided by 4. Gain is defined such that the average gain over all directions for an antenna with 100% electrical efficiency is equal to 1. Therefore, the effective area Aeff in terms of the gain G in a given direction is given by:
What must the relationship of an antenna and the receiving area be due to reciprocity?
A: proportional
Problem: Please answer a question about the following article about Light-emitting diode:
White light can be formed by mixing differently colored lights; the most common method is to use red, green, and blue (RGB). Hence the method is called multi-color white LEDs (sometimes referred to as RGB LEDs). Because these need electronic circuits to control the blending and diffusion of different colors, and because the individual color LEDs typically have slightly different emission patterns (leading to variation of the color depending on direction) even if they are made as a single unit, these are seldom used to produce white lighting. Nonetheless, this method has many applications because of the flexibility of mixing different colors, and in principle, this mechanism also has higher quantum efficiency in producing white light.[citation needed]
What colors are used to form white light?
A:
red, green, and blue