Does every scientific method begin with and observation?

Sara is creating an experiment. her hypothesis states the following. if i increase the air in my tires, then i will get better gas mileage. if this is her hypothesis what column titles do we need in our date table? a. air pressure in tire (psi) and gas mileage (mph) b. air pressure in the atmosphere (psi) and gas mileage (mph) c. miles (m) and gallons per mile (g) d. old battery and new battery

While listening to operatic solos, musicians process the lyrics and the tunes in separate brain areas. this most clearly illustrates the functioning of different

Which of the following harmful chemicals are found in tobacco smoke? a. carbon monoxide b. carbon dioxide c. nicotine b. carbon dioxide d. both a and c