Problem: Alloying copper with tin to make bronze was first practiced about 4000 years after the discovery of copper smelting, and about 2000 years after "natural bronze" had come into general use[citation needed]. Bronze artifacts from the Vinča culture date to 4500 BC. Sumerian and Egyptian artifacts of copper and bronze alloys date to 3000 BC. The Bronze Age began in Southeastern Europe around 3700–3300 BC, in Northwestern Europe about 2500 BC. It ended with the beginning of the Iron Age, 2000–1000 BC in the Near East, 600 BC in Northern Europe. The transition between the Neolithic period and the Bronze Age was formerly termed the Chalcolithic period (copper-stone), with copper tools being used with stone tools. This term has gradually fallen out of favor because in some parts of the world the Chalcolithic and Neolithic are coterminous at both ends. Brass, an alloy of copper and zinc, is of much more recent origin. It was known to the Greeks, but became a significant supplement to bronze during the Roman Empire.
When did the Bronze Age began in Southeastern Europe?
The answer is the following: 3700–3300 BC

Problem: The essential usefulness of a transistor comes from its ability to use a small signal applied between one pair of its terminals to control a much larger signal at another pair of terminals. This property is called gain. It can produce a stronger output signal, a voltage or current, which is proportional to a weaker input signal; that is, it can act as an amplifier. Alternatively, the transistor can be used to turn current on or off in a circuit as an electrically controlled switch, where the amount of current is determined by other circuit elements.
Why is a transistor so useful?
The answer is the following: gain

Problem: In 1841, Léon Escudier wrote of a recital given by Chopin that year, "One may say that Chopin is the creator of a school of piano and a school of composition. In truth, nothing equals the lightness, the sweetness with which the composer preludes on the piano; moreover nothing may be compared to his works full of originality, distinction and grace." Chopin refused to conform to a standard method of playing and believed that there was no set technique for playing well. His style was based extensively on his use of very independent finger technique. In his Projet de méthode he wrote: "Everything is a matter of knowing good fingering ... we need no less to use the rest of the hand, the wrist, the forearm and the upper arm." He further stated: "One needs only to study a certain position of the hand in relation to the keys to obtain with ease the most beautiful quality of sound, to know how to play short notes and long notes, and [to attain] unlimited dexterity." The consequences of this approach to technique in Chopin's music include the frequent use of the entire range of the keyboard, passages in double octaves and other chord groupings, swiftly repeated notes, the use of grace notes, and the use of contrasting rhythms (four against three, for example) between the hands.
What writing of Chopin talks about everything about piano playing has to do with proper fingering?
The answer is the following: his Projet de méthode

Problem: Mahayana Buddhism encourages everyone to become bodhisattvas and to take the bodhisattva vow, where the practitioner promises to work for the complete enlightenment of all beings by practicing the six pāramitās. According to Mahayana teachings, these perfections are: dāna, śīla, kṣanti, vīrya, dhyāna, and prajñā.
What buddhism encourages everyone to become bodhisattvas?
The answer is the following:
Mahayana