Problem: Incandescent light bulb:

The initial cost of an incandescent bulb is small compared to the cost of the energy it uses over its lifetime. Incandescent bulbs have a shorter life than most other lighting, an important factor if replacement is inconvenient or expensive. Some types of lamp, including incandescent and fluorescent, emit less light as they age; this may be an inconvenience, or may reduce effective lifetime due to lamp replacement before total failure. A comparison of incandescent lamp operating cost with other light sources must include illumination requirements, cost of the lamp and labor cost to replace lamps (taking into account effective lamp lifetime), cost of electricity used, effect of lamp operation on heating and air conditioning systems. When used for lighting in houses and commercial buildings, the energy lost to heat can significantly increase the energy required by a building's air conditioning system. During the heating season heat produced by the bulbs is not wasted, although in most cases it is more cost effective to obtain heat from the heating system. Regardless, over the course of a year a more efficient lighting system saves energy in nearly all climates.

What type of lighting system is less efficient over the course of a year?
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A: unanswerable

Problem: Department store:

Ireland developed a strong middle class, especially in the major cities, by the mid-nineteenth century. They were active patrons of department stores. Delany's New Mart was opened in 1853 in Dublin, Ireland. Unlike others, Delany's had not evolved gradually from a smaller shop on site. Thus it could claim to be the first purpose-built Department Store in the world. The word department store had not been invented at that time and thus it was called the "Monster House". The store was completely destroyed in the 1916 Easter Rising, but reopened in 1922.

When did Ireland begin to see a growth in its middle class?
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A: mid-nineteenth century.

Problem: Alexander Graham Bell:

The Bell family home was in Cambridge, Massachusetts, until 1880 when Bell's father-in-law bought a house in Washington, D.C., and later in 1882 bought a home in the same city for Bell's family, so that they could be with him while he attended to the numerous court cases involving patent disputes.

What did Bell have to go to court for in D.C.?
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A: patent disputes

Problem: Windows 8:

In February 2014, Bloomberg reported that Microsoft would be lowering the price of Windows 8 licenses by 70% for devices that retail under US$250; alongside the announcement that an update to the operating system would allow OEMs to produce devices with as little as 1 GB of RAM and 16 GB of storage, critics felt that these changes would help Windows compete against Linux-based devices in the low-end market, particularly those running Chrome OS. Microsoft had similarly cut the price of Windows XP licenses to compete against the early waves of Linux-based netbooks. Reports also indicated that Microsoft was planning to offer cheaper Windows 8 licenses to OEMs in exchange for setting Internet Explorer's default search engine to Bing. Some media outlets falsely reported that the SKU associated with this plan, "Windows 8.1 with Bing", was a variant which would be a free or low-cost version of Windows 8 for consumers using older versions of Windows. On April 2, 2014, Microsoft ultimately announced that it would be removing license fees entirely for devices with screens smaller than 9 inches, and officially confirmed the rumored "Windows 8.1 with Bing" OEM SKU on May 23, 2014.

When did Microsoft make the existence of Windows 9.1 with Bing OEM SKU official?
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A:
unanswerable