A thin walled double pipe counter flow heat exchanger.

What type of animal might be preserved in a tar pit

Two technicians are discussing how to test a car's exhaust by holding a small piece of paper within an inch of the tailpipe mouth. technician a says that if the paper is vibrating due to a "puffing" output from the tailpipe, this signals a smoothly running engine. technician b says that if the paper is being drawn toward the tailpipe, this could indicate burned exhaust valves. who is correct? a. technician b b. both technicians a and b c. technician a d. neither technicians a or b

This graph represents four ecosystems. each ecosystem has a different number of species, adding to its biodiversity. different colors represent different species. which statements correctly summarize the data depicted by the graph? 1. ecosystem d has more biodiversity than ecosystem c. 2. ecosystem b has more biodiversity than all the other ecosystems. 3. ecosystem a has more biodiversity than ecosystem b but less biodiversity than ecosystem c. 4. ecosystem b has more biodiversity than ecosystems c and d but less biodiversity than ecosystem a. 5. ecosystem a has more biodiversity than ecosystem c but less biodiversity than ecosystem b.