PLEASE HELP ASAP I NEED TO SUBMIT NOW
How are the respiratory and circulatory systems similar?

A - Both systems provide glucose and other substances to cells.
B - Both systems regulate blood flow throughout the body.
C - Both systems help remove carbon dioxide from the body.
D - Both systems send messages to the nervous system for breathing.

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?