QUES: Manufacturers of devices may have their own proprietary numbering system, for example CK722. Since devices are second-sourced, a manufacturer's prefix (like "MPF" in MPF102, which originally would denote a Motorola FET) now is an unreliable indicator of who made the device. Some proprietary naming schemes adopt parts of other naming schemes, for example a PN2222A is a (possibly Fairchild Semiconductor) 2N2222A in a plastic case (but a PN108 is a plastic version of a BC108, not a 2N108, while the PN100 is unrelated to other xx100 devices).
Who decided what letters were in the manufacturer's prefixes?

ANS: unanswerable

QUES: Recent developments in LEDs permit them to be used in environmental and task lighting. LEDs have many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved physical robustness, smaller size, and faster switching. Light-emitting diodes are now used in applications as diverse as aviation lighting, automotive headlamps, advertising, general lighting, traffic signals, camera flashes and lighted wallpaper. As of 2015[update], LEDs powerful enough for room lighting remain somewhat more expensive, and require more precise current and heat management, than compact fluorescent lamp sources of comparable output.
Why aren't some people hesitant to use LED lighting?

ANS: unanswerable

QUES: Another significant change undergone by many of these newly agrarian communities was one of diet. Pre-agrarian diets varied by region, season, available local plant and animal resources and degree of pastoralism and hunting. Post-agrarian diet was restricted to a limited package of successfully cultivated cereal grains, plants and to a variable extent domesticated animals and animal products. Supplementation of diet by hunting and gathering was to variable degrees precluded by the increase in population above the carrying capacity of the land and a high sedentary local population concentration. In some cultures, there would have been a significant shift toward increased starch and plant protein. The relative nutritional benefits and drawbacks of these dietary changes and their overall impact on early societal development is still debated.
What forms of availability dictated Pre-agrarian diets?

ANS: local plant and animal resources

QUES: In the 1980s, 1990s, and 2000s, terrorist attacks in Egypt became numerous and severe, and began to target Christian Copts, foreign tourists and government officials. In the 1990s an Islamist group, Al-Gama'a al-Islamiyya, engaged in an extended campaign of violence, from the murders and attempted murders of prominent writers and intellectuals, to the repeated targeting of tourists and foreigners. Serious damage was done to the largest sector of Egypt's economytourismand in turn to the government, but it also devastated the livelihoods of many of the people on whom the group depended for support.
What was the name of a high profile terrorist group in Egypt in 1990s?

ANS:
Al-Gama'a al-Islamiyya