What must happen for a solar eclipse to occur?
a) the moon must be full.
b) the moon must pass behind earth.
c) the moon’s orbit must cross the plane of the ecliptic.
d) the moon’s orbit must not cross earth’s penumbra.

Consider the last statement in the prompt: "people take such environmental factors into account in their choices when deciding where to live." do all people have a choice as to where they live? what factor plays a key role in this decision and may therefore play a large role in determining quality of life?

Microorganisms are involved in each of the following processes excepta. smog production. b. food production. c. infection. d. o2 production. e. decomposition of organic material.

The carbon cycle is best defined as a process in which a. carbon changes from inorganic forms to organic forms and back b. carbon is changed into other elements such as oxygen or nitrogen c. carbon is continually created from the sun’s energy by plants d. carbon is consumed and regenerated from other elements such as oxygen and nitrogen