Astudent creates a model of a closed ecosystem by filling a glass tank half full with water, then adding 10 snails and two small aquatic plants. the next day, all the snails are dead . what is the most likely cause of their death?

The valve seat performs two functions: it provides a seal for the valve in the combustion chamber, and it provides a cool surface to carry heat away from the valve. most valves use a seating angle.

Two technicians are discussing oil changes. technician a says that waste oil and old filters need to be disposed of according to the law. technician b says that old filters can be returned to the parts department for a core value. which technician is correct?           a. technician a only   b. both technicians a and b   c. technician b only   d. neither technician a nor b

Psycoloshist albert bandits developed a theory of