I just took a test in school today. What question was I asked?

Question I was asked: When a switch to a ceiling fan is turned on, electrical energy is being transformed into

I just took a test in school today. What question was I asked?

Question I was asked: When oxygen combines with hydrogen, which substance is formed?

I just took a test in school today. What question was I asked?

Question I was asked:
Certain fossils can be used to help determine the age of the rock layer in which the fossils are found. Which type of fossil is best to use when making this determination?