Interconnected canals and hollow tube feet work together in a sea star’s
a. digestive system.
c. circulatory system.
b. respiratory system.
d. water-vascular system.

Exercise has no positive effects on the nervous system? true or falseu

Which practice is harmful to the land? a. using animal waste as fertilizer b. composting with peels from commercial fruit c. throwing paint cans in the garbage d. cutting the lawn with a gas-powered mower

About how many individuals in the us go bankrupt each year due to medical bills?