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Prior to Einstein's paper, electromagnetic radiation such as visible light was considered to behave as a wave: hence the use of the terms "frequency" and "wavelength" to characterise different types of radiation. The energy transferred by a wave in a given time is called its intensity. The light from a theatre spotlight is more intense than the light from a domestic lightbulb; that is to say that the spotlight gives out more energy per unit time and per unit space(and hence consumes more electricity) than the ordinary bulb, even though the colour of the light might be very similar. Other waves, such as sound or the waves crashing against a seafront, also have their own intensity. However, the energy account of the photoelectric effect didn't seem to agree with the wave description of light.
What does it mean for a light source to be more intense than another?
A: gives out more energy per unit time and per unit space

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The Finnish and Baltic invasions began a deterioration of relations between the Soviets and Germany. Stalin's invasions were a severe irritant to Berlin, as the intent to accomplish these was not communicated to the Germans beforehand, and prompted concern that Stalin was seeking to form an anti-German bloc. Molotov's reassurances to the Germans, and the Germans' mistrust, intensified. On June 16, as the Soviets invaded Lithuania, but before they had invaded Latvia and Estonia, Ribbentrop instructed his staff "to submit a report as soon as possible as to whether in the Baltic States a tendency to seek support from the Reich can be observed or whether an attempt was made to form a bloc."
Who wanted to know the moment an anti-german bloc was to form?
A: Ribbentrop

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IMF's forecast said that Greece's unemployment rate would hit the highest 14.8 percent in 2012 and decrease to 14.1 in 2014. But in fact, the Greek economy suffered a prolonged high unemployemnt. The unemployment figure was between 9 per cent and 11 per cent in 2009, and it soared to 28 per cent in 2013. In 2015, Greece's jobless rate is around 24 per cent. It is thought that Greece's potential output has been eroded by this prolonged massive unemployment due to the associated hysteresis effects.
What was Greece's employment rate between 2000 and 2009?
A: unanswerable

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The halogen lamp reduces uneven evaporation of the filament and eliminates darkening of the envelope by filling the lamp with a halogen gas at low pressure, rather than an inert gas. The halogen cycle increases the lifetime of the bulb and prevents its darkening by redepositing tungsten from the inside of the bulb back onto the filament. The halogen lamp can operate its filament at a higher temperature than a standard gas filled lamp of similar power without loss of operating life. Such bulbs are much smaller than normal incandescent bulbs, and are widely used where intense illumination is needed in a limited space. Fiber-optic lamps for optical microscopy is one typical application.
What is the most common situation when a halogen bulb is used?
A:
where intense illumination is needed in a limited space