Compare and contrast the body of a crayfish with that of an insect.

Insects have a distinct set of characteristics which all must have if they are insects. They must have three pairs of legs (even though sometimes they may appear different as larvae, such as caterpillars), a set of mouth parts, and a head, thorax, and abdomen.

this age may represent the age of the earth's accretion, of core formation, or of the material from which the earth formed. this dating is based on evidence from radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.

the most common type of reef is the fringing reef. this type of reef grows seaward directly from the shore. they form borders along the shoreline and surrounding islands.