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No single feature distinguishes Annelids from other invertebrate phyla, but they have a distinctive combination of features. Their bodies are long, with segments that are divided externally by shallow ring-like constrictions called annuli and internally by septa ("partitions") at the same points, although in some species the septa are incomplete and in a few cases missing. Most of the segments contain the same sets of organs, although sharing a common gut, circulatory system and nervous system makes them inter-dependent. Their bodies are covered by a cuticle (outer covering) that does not contain cells but is secreted by cells in the skin underneath, is made of tough but flexible collagen and does not molt on the other hand arthropods' cuticles are made of the more rigid -chitin, and molt until the arthropods reach their full size. Most annelids have closed circulatory systems, where the blood makes its entire circuit via blood vessels.
What covers an annelid's exterior?
A: a cuticle

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Oklahoma had 598 incorporated places in 2010, including four cities over 100,000 in population and 43 over 10,000. Two of the fifty largest cities in the United States are located in Oklahoma, Oklahoma City and Tulsa, and 65 percent of Oklahomans live within their metropolitan areas, or spheres of economic and social influence defined by the United States Census Bureau as a metropolitan statistical area. Oklahoma City, the state's capital and largest city, had the largest metropolitan area in the state in 2010, with 1,252,987 people, and the metropolitan area of Tulsa had 937,478 residents. Between 2000 and 2010, the cities that led the state in population growth were Blanchard (172.4%), Elgin (78.2%), Jenks (77.0%), Piedmont (56.7%), Bixby (56.6%), and Owasso (56.3%).
How many people live in the Tulsa metro area?
A: 937,478

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The continuous torque density of conventional electric machines is determined by the size of the air-gap area and the back-iron depth, which are determined by the power rating of the armature winding set, the speed of the machine, and the achievable air-gap flux density before core saturation. Despite the high coercivity of neodymium or samarium-cobalt PMs, continuous torque density is virtually the same amongst electric machines with optimally designed armature winding sets. Continuous torque density relates to method of cooling and permissible period of operation before destruction by overheating of windings or PM damage.
What does continuous torque density refer to?
A: method of cooling and permissible period of operation before destruction by overheating

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Slavery and slaves were part of the social order; there were slave markets where they could be bought and sold. Many slaves were freed by the masters for services rendered; some slaves could save money to buy their freedom. Generally, mutilation and murder of slaves was prohibited by legislation. However, Rome did not have a law enforcement arm. All actions were treated as "torts," which were brought by an accuser who was forced to prove the entire case himself. If the accused were a noble and the victim, not a noble, the likelihood of finding for the accused was small. At most, the accused might have to pay a fine for killing a slave. It is estimated that over 25% of the Roman population was enslaved.
Where in the Roman Republic could slaves be acquired?
A:
slave markets