HELP ME PLZ What does a "backflow preventer device" do? a
Keeps your irrigation system clear of sand and insects?
b
Prevents super high water pressure?
c
Keeps drip nozzles from being blown off the tubing?
d
Stops water from flowing back into the house water and contaminating it?

Which of the following discoveries would be most likely to cause a scientific paradigm shift? a. the discovery of more rings around uranus b. the discovery of a new pathogenic virus transmitted by mosquitoes c. the discovery that a dormant volcano is showing signs of activity d. the discovery of a new species of salamander in the amazon rainforest e. the discovery that excess heat is radiating from the center of the earth and causing global climate change