Which organ systems deliver oxygen to body cells?
a. respiratory and excretory systems
b. muscular and immune systems
c. respiratory and circulatory systems
d. endocrine and lymphatic systems

Is it considered muscle s ennervation if sympathetic fibers innervate the vessels within the muscle?

The body is protected against harmful flu viruses by

Elephants in the savanna regions of africa dig holes in dried up river beds to reach water lying just below the surface. these holes provide drinking water for other animals as well. so, without the elephants, many animals might otherwise die from lack of water during the dry season. the location in which the elephants live is an example of a/n and the role they play in creating water holes is an example of a a) ecosystem; habitat b) community; niche c) habitat; niche d) niche; habitat