Nexpow Car Rooftop Cargo Carrier Bag, 21 Cubic Feet 100% Waterproof Heavy Duty 840D Car Roof Bag for All Vehicle with/Without Racks

100 or one hundred (Roman numeral: C) is the natural number following 99 and preceding 101.

Twenty-one, XXI or 21 may refer to:

• 21 (number), the natural number following 20 and preceding 22
• The years 21 BC, AD 21, 1921, 2021

A bag (also known regionally as a sack) is a common tool in the form of a non-rigid container, typically made of cloth, leather, bamboo,paper, or plastic. The use of bags predates recorded history, with the earliest bags being lengths of animal skin, cotton, or woven plant fibers, folded up at the edges and secured in that shape with strings of the same material. Bags can be used to carry items such as personal belongings, groceries, and other objects. They comes in various shapes and sizes, often equipped with handles or straps for easier carrying.

Bags have been fundamental for the development of human civilization, as they allow people to easily collect and carry loose materials, such as berries or food grains, also allowing them to carry more items in their hands.

The word probably has its origins in the Norse word baggi, from the reconstructed Proto-Indo-European bʰak, but is also comparable to the Welsh baich (load, bundle), and the Greek Τσιαντουλίτσα (Chandulícha, load).

Cheap disposable paper bags and plastic shopping bags are very common, varying in size and strength in the retail trade as a convenience for shoppers, and are often supplied by the shop for free or for a small fee. Customers may also take their own shopping bag(s) to use in shops.

Although paper had been used for wrapping and padding in Ancient China since the 2nd century BC, the first use of paper bags in China (for preserving the flavor of tea) came during the later Tang dynasty (618–907 AD).

A car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people over cargo. There are around one billion cars in use worldwide. The car is considered an essential part of the developed economy.

The French inventor Nicolas-Joseph Cugnot built the first steam-powered road vehicle in 1769, while the Swiss inventor François Isaac de Rivaz designed and constructed the first internal combustion-powered automobile in 1808. The modern car—a practical, marketable automobile for everyday use—was invented in 1886, when the German inventor Carl Benz patented his Benz Patent-Motorwagen. Commercial cars became widely available during the 20th century. The 1901 Oldsmobile Curved Dash and the 1908 Ford Model T, both American cars, are widely considered the first mass-produced and mass-affordable cars, respectively. Cars were rapidly adopted in the US, where they replaced horse-drawn carriages. In Europe and other parts of the world, demand for automobiles did not increase until after World War II. In the 21st century, car usage is still increasing rapidly, especially in China, India, and other newly industrialised countries.

Cars have controls for driving, parking, passenger comfort, and a variety of lamps. Over the decades, additional features and controls have been added to vehicles, making them progressively more complex. These include rear-reversing cameras, air conditioning, navigation systems, and in-car entertainment. Most cars in use in the early 2020s are propelled by an internal combustion engine, fueled by the combustion of fossil fuels. Electric cars, which were invented early in the history of the car, became commercially available in the 2000s and are predicted to cost less to buy than petrol-driven cars before 2025. The transition from fossil fuel-powered cars to electric cars features prominently in most climate change mitigation scenarios, such as Project Drawdown's 100 actionable solutions for climate change.

There are costs and benefits to car use. The costs to the individual include acquiring the vehicle, interest payments (if the car is financed), repairs and maintenance, fuel, depreciation, driving time, parking fees, taxes, and insurance. The costs to society include maintaining roads, land-use, road congestion, air pollution, noise pollution, public health, and disposing of the vehicle at the end of its life. Traffic collisions are the largest cause of injury-related deaths worldwide. Personal benefits include on-demand transportation, mobility, independence, and convenience. Societal benefits include economic benefits, such as job and wealth creation from the automotive industry, transportation provision, societal well-being from leisure and travel opportunities, and the generation of revenue from taxation. People's ability to move flexibly from place to place has far-reaching implications for the nature of societies.

In transportation, freight refers to goods conveyed by land, water or air, while cargo refers specifically to freight when conveyed via water or air. In economics, freight refers to goods transported at a freight rate for commercial gain. The term cargo is also used in case of goods in the cold-chain, because the perishable inventory is always in transit towards a final end-use, even when it is held in cold storage or other similar climate-controlled facilities, including warehouses.

Multi-modal container units, designed as reusable carriers to facilitate unit load handling of the goods contained, are also referred to as cargo, especially by shipping lines and logistics operators. When empty containers are shipped each unit is documented as a cargo and when goods are stored within, the contents are termed containerized cargo. Similarly, aircraft ULD boxes are also documented as cargo, with an associated packing list of the items contained within.

A duty (from "due" meaning "that which is owing"; Old French: deu, did, past participle of devoir; Latin: debere, debitum, whence "debt") is a commitment or expectation to perform some action in general or if certain circumstances arise. A duty may arise from a system of ethics or morality, especially in an honor culture. Many duties are created by law, sometimes including a codified punishment or liability for non-performance. Performing one's duty may require some sacrifice of self-interest.

A sense-of-duty is also a virtue or personality trait that characterizes someone who is diligent about fulfilling individual duties or who confidently knows their calling. A sense-of-duty can also come from a need to fulfill familial pressures and desires. This is typically seen in a militaristic/patriotic way.

Cicero, an early Roman philosopher who discusses duty in his work “On Duties", suggests that duties can come from four different sources:

1. as a result of being a human
2. as a result of one's particular place in life (one's family, one's country, one's job)
3. as a result of one's character
4. as a result of one's own moral expectations for oneself

The specific duties imposed by law or culture vary considerably, depending on jurisdiction, religion, and social normalities.

A roof (pl.: roofs or rooves) is the top covering of a building, including all materials and constructions necessary to support it on the walls of the building or on uprights, providing protection against rain, snow, sunlight, extremes of temperature, and wind. A roof is part of the building envelope.

The characteristics of a roof are dependent upon the purpose of the building that it covers, the available roofing materials and the local traditions of construction and wider concepts of architectural design and practice, and may also be governed by local or national legislation. In most countries, a roof protects primarily against rain. A verandah may be roofed with material that protects against sunlight but admits the other elements. The roof of a garden conservatory protects plants from cold, wind, and rain, but admits light.

A roof may also provide additional living space, for example, a roof garden.

A vehicle (from Latin vehiculum) is a machine designed for self-propulsion, usually to transport people, cargo, or both. Vehicles include wagons, bicycles, motor vehicles (motorcycles, cars, trucks, buses, mobility scooters), railed vehicles (trains, trams), watercraft (ships, boats, underwater vehicles), amphibious vehicles (screw-propelled vehicles, hovercraft), aircraft (airplanes, helicopters, aerostats), and spacecraft.

Ground vehicles can be broadly classified by the type of contact with the ground: wheels, tracks, rails, or skis. ISO 3833-1977 is the international standard for road vehicle types, terms, and definitions.

With or WITH may refer to:

• With, a preposition in English
• Carl Johannes With (1877–1923), Danish doctor and arachnologist
• With (character), a character in D. N. Angel
• With (novel), a novel by Donald Harrington
• With (album), a 2014 album by TVXQ
• With (EP), a 2021 EP by Nam Woo-hyun

Without may refer to:

• Without, an English preposition
• "Without" (The X-Files), an episode in the eighth season of The X-Files
• Without, a film that premiered at the 2011 Slamdance Film Festival
• "Without", a song by Jack Savoretti from the album Between the Minds, 2007
• "Without", a song by Pino, 2021
• "Without", a song by Brett Kissel from the album What Is Life?, 2021