Earth's atmosphere is unable to retain hydrogen and helium because of their

Rarefaction is used for which of the following? a. creating a representative sample b. studying how disease impacts populations c. rediscovering species thought to be instinct d. determining which sea creatures live in an area

Babies with very low or very high birth weight are less likely to survive. observe a graph of the data.

The human body needs energy in order to carry out life processes such as breathing. where does the body get this energy? a. from eating food b. from learning about new things c. from lying in the sun d. from sleeping