math/logic
This number is approximated as 3.14, and is the ratio of the circumference of a circle to its diameter in Euclidean geometry.
What is Pi?
This country declared "war" on emus.
What is Australia?
This animal often lives in modern houses.
What are humans?
This can theoretically travel at the speed of light.
What is light?
If a statement is true, this other statement must also be true.
What is the contrapositive?
Most people cut this object for hygiene or cultural purposes.
What is hair?
This molecule with acidic properties has the highest pH.
What is water?
This mixture covers >75% of the Earth's surface.
What is air?
These two products are formed in the reaction of sodium hydroxide and hydrochloric acid.