Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Energy from the Sun comes from the lightest element, hydrogen, fusing together to create the second lightest element, helium. Nuclear fusion on the Sun releases tremendous amounts of solar energy. The energy travels to the Earth, mostly as visible light. The light carries the energy through the empty space between the Sun and the Earth as radiation. Solar energy has been used for power on a small scale for hundreds of years, and plants have used it for billions of years. Unlike energy from fossil fuels, which almost always come from a central power plant or refinery, solar power can be harnessed locally (Figure 1.1). A set of solar panels on a homes rooftop can be used to heat water for a swimming pool or can provide electricity to the house. Societys use of solar power on a larger scale is just starting to increase. Scientists and engineers have very active, ongoing research into new ways to harness energy from the Sun more efficiently. Because of the tremendous amount of incoming sunlight, solar power is being developed in the United States in southeastern California, Nevada, and Arizona. Solar panels supply power to the Interna- tional Space Station. Solar power plants turn sunlight into electricity using a large group of mirrors to focus sunlight on one place, called a receiver (Figure 1.2). A liquid, such as oil or water, flows through this receiver and is heated to a high temperature by the focused sunlight. The heated liquid transfers its heat to a nearby object that is at a lower temperature through a process called conduction. The energy conducted by the heated liquid is used to make electricity. This solar power plant uses mirrors to focus sunlight on the tower in the center. The sunlight heats a liquid inside the tower to a very high temperature, producing energy to make electricity. Solar energy has many benefits. It is extremely abundant, widespread, and will never run out. But there are problems with the widespread use of solar power. Sunlight must be present. Solar power is not useful in locations that are often cloudy or dark. However, storage technology is being developed. The technology needed for solar power is still expensive. An increase in interested customers will provide incentive for companies to research and develop new technologies and to figure out how to mass-produce existing technologies (Figure 1.3). Solar panels require a lot of space. Fortunately, solar panels can be placed on any rooftop to supply at least some of the power required for a home or business. This experimental car is one example of the many uses that engineers have found for solar energy. Click image to the left or use the URL below. URL: Click image to the left or use the URL below. URL:
the source of solar power is nuclear

Everywhere man is altering the balance of nature.He is facilitating the spread of plants and animals into new regions, sometimes deliberately, sometimes unconsciously.He is covering huge areas with new kinds of plants, or with houses, factories, slag-heaps and other products of his civilization.He exterminates some species on a large scale, but favours the multiplication of others.In brief, he has done more in five thousand years to alter the biological aspect of the planet than has nature in five million. Many of these changes which he has brought about have had unforeseen consequences.Who would have thought that the throwing away of a piece of Canadian waterweed would have caused half the waterways of Britain to be blocked for a decade, or that the provision of pot cacti for lonely settlers' wives would have led to Eastern Australian being overrun with forests of Prickly Pear? Who would have prophesied that the cutting down of forests on the Adriatic coasts, or in parts of Central Africa, could have reduced the land to a semidesert, with the very soil washed away from the bare rock? Who would have thought that improved communications would have changed history by the spreading of disease-sleeping sickness into East Africa, measles into Oceania, very possibly malaria into ancient Greece? These are spectacular examples; but examples on a smaller scale are everywhere to be found.We make a nature sanctuary for rare birds, prescribing absolute security for all species; and we may find that some common and hardy kind of bird multiplies beyond measure and ousts the rare kinds in which we were particularly interested.We see, owing to some little change brought about by civilization, the starling spread over the English country-side in hordes.We improve the yielding capacities of our cattle; and find that now they exhaust the pastures which sufficed for less exigent stock.
What have spread diseases?

Tick-Tock appeared as part of the ''Night Shift'' entry in the Official Handbook of the Marvel Universe Update '89 #5.
In which fictional universe does Tick-Tock exist?