a retractable service pit cover can help other shop employees from falling into the pit while another technician is in the pit servicing a car.

Afood web shows who eats who in any given habitat. every living thing, from one-celled algae to giant blue whales, needs food to survive. each food web is a possible pathway that energy and matter can follow through the habitat. a food web begins with producers: organisms that convert sunlight into usable chemical energy. the food web is completed by the decomposers who turn organic wastes, such as decaying plants, into inorganic materials, such as nutrient-rich soil. decomposers complete the cycle of life, returning nutrients to the soil or oceans for use by producers. in this food web, identify the decomposer.

Scientists observed a rock stratum with fossil. if mollusks evolved before arthropod, where will their fossils be found.

Why are gold and platinum used for jewelry