Most important building block of responsibility

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

If inflation is 6% and nominal gdp grew by 4%, then during the same period real gdp changed by a) -2% b) 2% c) 4% d) 5%

Which statements are true for invasive species? 1. they always stabilize an ecosystem. 2. they’re always successful in adjusting to a new habitat. 3. they often compete with the native species for resources. 4. they have the ability to displace the native species. 5. they’re always pests.