Granite-a very hard, grey, pink, or black rock, used for building
noun- The nature of this granite is very hard and strong.
limestone-a white or light grey rock that is used as a building material and in the making of cement
noun- In Spain you find three kinds: granite, limestone and conglomerates.
marble-a type of very hard rock that has a pattern of lines going through it, feels cold, and can be polished to become smooth and shiny:
noun- The big slabs of granite or marble are very expansive.
paleontologist-noun
Uh, paleontologist Georges Cuvier discovered that species could go extinct.
prehistoric times-noun
The valley is an important finding fossils from prehistoric times.
amphibian-an animal, such as a frog, that lives both on land and in water but must produce its eggs in water
noun-These chemicals pose a threat to human and amphibian health.
arthropod-a type of animal with no spine, a hard outer skin, legs with bones joined together, and a body divided into different parts, for example a spider, crab, or ant
noun- Other viruses are transmitted by the bite of an infected arthropod.
bacteria-very small organisms that are found everywhere and are the cause of many diseases
noun-The agent of anthrax is a bacterium called Bacillus anthracis.
insect-a type of very small animal with six legs, a body divided into three parts and usually two pairs of wings, or, more generally, any similar very small animal
noun-To check this insect you can consult the present sheet.
mammal-any animal of which the female feeds her young on milk from her own body. Most mammals give birth to live young, not eggs:
noun-The elephant's the only mammal that can't jump.
reptile-an animal that produces eggs and uses the heat of the sun to keep its blood warm
noun- During these expeditions, three new reptile species have been discovered.
worms-a small animal with a long, narrow, soft body without arms, legs, or bones:
noun-The worms are about one half inch (1 centimeter) long.
asteroid-one of many large rocks that circle the sun
noun-A comet or asteroid had collided with the giant planet.
earth-the planet third in order of distance from the sun, between Venus and Mars; the world on which we live:
noun-The earth has lost much of its splendor and majesty.
ocean-a very large area of sea:
noun-In Barcelona, the island is big and the ocean small
chemical-any basic substance that is used in or produced by a reaction involving changes to atoms or molecules
noun-Many of us live in communities that contain chemical refineries.
