Question 3 of 25 Which two explanations are based on personal beliefs?
D A Data gathered during experiments show that there is an inverse
relationship between the force of gravity and distance.
B. Certain mineral crystals have properties that help protect the
body from illness.
C. Medical data gathered over many years show that lack of
adequate sleep causes health problems.
D. A constellatioris position in the night sky can be used to predict
events in a person's life.
O E Observations using microscopes reveal that all known organisms
are composed of tiny structures called cells.

Dry ice is solid carbon dioxide that is used in the transport of food and medicine. dry ice becomes a gas at –78.5°c without becoming a liquid first.

Astudent is performing an experiment comparing sound and light waves. the student gathers the following data. what conclusion does the student most likely make based on this data? light waves always travel the same speed; however, the speed of sound is determined by the medium that it travels through. all sound waves always have the same energy, so the temperature of the medium does not affect wave speed. light needs to vibrate particles, so it travels fastest in tightly packed solids, while sound does not need a medium, so it travels fastest in a gas. tightly packed particles in solids slow down the light waves; however, sound waves make particles bounce into each other, so they travel faster in solids.

The focal length of a relaxed human eye is approximately 1.7 cm. when we focus our eyes on a close up object, we can change the refractive power of the eye by about 16 diopters. (a) does the refractive power of our eyes increase or decrease by 16 diopters when we focus closely? explain. (b) calculate the focal length of the eye when we focus closely.