Which explanation is based on scientific evidence? A. Observations made using microscopes reveal that all known
organisms are composed of tiny structures called cells.
B. Magnets have hidden powers that can have health effects.
C. Performing good deeds for other people will make a person happy.
D. illnesses are caused by bad smells in the air.

Astudent looks at ocean waves coming into the beach. an ocean wave with more energy will a) have a greater height. b) have a greater period. c) travel toward the beach faster. d) strike the beach with greater frequency.

With the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 1.90

Which of the following is the main energy source for the sun? a. fission of hydrogen b. fusion of hydrogen c. fusion of helium d. fission of iron