A vehicle (from Latin: vehiculum) is a machine that transports people or cargo. Vehicles include wagons, bicycles, motor vehicles (motorcycles, cars, trucks, buses, mobility scooters for disabled people), railed vehicles (trains, trams), watercraft (ships, boats, underwater vehicles), amphibious vehicles (screw-propelled vehicles, hovercraft),  aircraft (airplanes, helicopters, aerostats) and spacecraft.Land vehicles are classified broadly by what is used to apply steering and drive forces against the ground: wheeled, tracked, railed or skied. ISO 3833-1977 is the standard, also internationally used in legislation, for road vehicles types, terms and definitions. History
The oldest boats found by archaeological excavation are logboats, with the oldest logboat found, the Pesse canoe found in a bog in the Netherlands, being carbon dated to 8040 - 7510 BC, making it 9,500–10,000 years old,
a 7,000-year-old seagoing boat made from reeds and tar has been found in Kuwait. Boats were used between 4000 -3000 BC in Sumer, ancient Egypt and in the Indian Ocean. There is evidence of camel pulled wheeled vehicles about 4000–3000 BC. The earliest evidence of a wagonway, a predecessor of the railway, found so far was the 6 to 8.5 km (4 to 5 mi) long Diolkos wagonway, which transported boats across the Isthmus of Corinth in Greece since around 600 BC. Wheeled vehicles pulled by men and animals ran in grooves in limestone, which provided the track element, preventing the wagons from leaving the intended route. In 200 CE, Ma Jun built a south-pointing chariot, a vehicle with an early form of guidance system.
Pediatric endocrinologists were the only physicians interested in the arcana of GH metabolism and childrens growth, but their previously academic arguments took on new practical significance with major financial implications. The major scientific arguments dated back to the days of GH scarcity:
Everyone agrees on the nature and diagnosis of severe GH deficiency, but what are the edges and variations? How should marked constitutional delay be distinguished from partial GH deficiency? To what extent is "normal shortness" a matter of short children naturally making less growth hormone? Can a child make GH in response to a stimulation test but fail to make enough in "daily life" to grow normally? If a stimulation test is used to define deficiency, what GH cutoff should be used to define normal?It was the ethical questions that were new. Is GH not a wise use of finite healthcare resources, or is the physicians primary responsibility to the patient? If GH is given to most extremely short children to make them taller, will the definition of “extremely short” simply rise, negating the expected social benefit? If GH is given to short children whose parents can afford it, will shortness become a permanent mark of lower social origins? More of these issues are outlined in the ethics section. Whole meetings were devoted to these questions; pediatric endocrinology had become a specialty with its own bioethics issues. Despite the price, the 1990s became an era of experimentation to see what else growth hormone could help.