How are hind limbs and forelimbs different?

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

The graph shows a trend in an ecosystem over time caused by increased pollution in the region. what can you conclude from the graph? a. there’s lower biodiversity among birds. b. there’s a higher reproductive rate among birds. c. there’s a significant decline in the number of producers. d. other types of animals were unaffected by pollution.

Based on calculations, students should have 10.4 grams of powder after conducting an experiment. the students get these results: 10.2 grams, 10.4 grams, 10.3 grams, 10.4 grams, and 10.5 grams. which words best describe this data? check all that apply. a- accurate b- falsified c-invalid d-precise e-redundant