For a solar eclipse to occur

a. the sun must be directly between earth and the moon

b. the moon must be directly between earth and the sun

c. the moon must be directly behind earth

d. earth must be directly between the sun and the moon

Acell in the human nervous system whose primary function is to form myelin and the blood-brain barrier, respond to injury, remove debris, and enhance learning and memory is called a(n) cell.

The serengeti plains are part of the african savanna ecosystem and are home to a variety of different species of plants and animals. the serengeti plains experience a seven-month period of seasonal drought each year, during which the ecosystem receives only four inches of rain and the availability of some resources becomes very scarce. which type of limiting factors does the seasonal drought in the serengeti plains affect?

Tom wants to conduct a scientific study but he needs to finish by the end of the school year. what practical way could tom work around this limitation and be successful in his study?