Which natural satellite is the only one orbiting Earth and significantly influences ocean tides?

Which common food borne bacterial disease causes prolonged fever and is transmitted through contaminated food and water?

Which common household chemical reaction produces a foaming effect often used in classroom volcano experiments?

Which gas is most abundant in the Earth's atmosphere?

Which part of the human brain regulates vital involuntary functions such as breathing and heartbeat?

Which type of immunity is gained through vaccination by introducing a weakened or inactivated pathogen?