Problem: Because of their long life, fast switching times, and their ability to be seen in broad daylight due to their high output and focus, LEDs have been used in brake lights for cars' high-mounted brake lights, trucks, and buses, and in turn signals for some time, but many vehicles now use LEDs for their rear light clusters. The use in brakes improves safety, due to a great reduction in the time needed to light fully, or faster rise time, up to 0.5 second faster[citation needed] than an incandescent bulb. This gives drivers behind more time to react. In a dual intensity circuit (rear markers and brakes) if the LEDs are not pulsed at a fast enough frequency, they can create a phantom array, where ghost images of the LED will appear if the eyes quickly scan across the array. White LED headlamps are starting to be used. Using LEDs has styling advantages because LEDs can form much thinner lights than incandescent lamps with parabolic reflectors.
Because of their high output, LED lights are very useful where?
The answer is the following: brake lights for cars

Problem: Victoria wrote to her uncle Leopold, whom Victoria considered her "best and kindest adviser", to thank him "for the prospect of great happiness you have contributed to give me, in the person of dear Albert ... He possesses every quality that could be desired to render me perfectly happy. He is so sensible, so kind, and so good, and so amiable too. He has besides the most pleasing and delightful exterior and appearance you can possibly see." However at 17, Victoria, though interested in Albert, was not yet ready to marry. The parties did not undertake a formal engagement, but assumed that the match would take place in due time.
Who was Victoria not ready to marry at age 17?
The answer is the following: Albert

Problem: Studies of nutritional status must take into account the state of the body before and after experiments, as well as the chemical composition of the whole diet and of all material excreted and eliminated from the body (in urine and feces). Comparing the food to the waste can help determine the specific compounds and elements absorbed and metabolized in the body. The effects of nutrients may only be discernible over an extended period, during which all food and waste must be analyzed. The number of variables involved in such experiments is high, making nutritional studies time-consuming and expensive, which explains why the science of animal nutrition is still slowly evolving.
What needs to be compared to the waste products from humans to determine what is absorbed in the body?
The answer is the following: food

Problem: London's buildings are too diverse to be characterised by any particular architectural style, partly because of their varying ages. Many grand houses and public buildings, such as the National Gallery, are constructed from Portland stone. Some areas of the city, particularly those just west of the centre, are characterised by white stucco or whitewashed buildings. Few structures in central London pre-date the Great Fire of 1666, these being a few trace Roman remains, the Tower of London and a few scattered Tudor survivors in the City. Further out is, for example, the Tudor period Hampton Court Palace, England's oldest surviving Tudor palace, built by Cardinal Thomas Wolsey c.1515.
Of what material is London's National Gallery made?
The answer is the following:
Portland stone