What most likely happened in sediment layer 5?
a massive volcano erupted, causing global warming and
lava flow, which in turn caused mass extinction
more iridium was produced by space objects and
dumped by local factories.
a massive dust cloud formed, causing global cooling
and a lack of sunshine. this in turn caused a lack of
plants and a mass extinction
fewer impacts lead to a drop in iridium levels and a
mass extinction caused by a lack of sunshine

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