Infants can sit with support when they're approximately old.
a. six months
b. two months
c. four months
d. one month

Which nutrient is the most difficult to break down and, thus, is generally used last fro energy in the body? water carbohydrates fats proteins

What effect do stimulants, such as cocaine, have on the nervous system? o a. stimulants change the activity of neurotransmitters. o b. stimulants mimic hormones and influence moods. o o c. stimulant|mchange how sensory information is processed. d. stimulants decrease brain activity.

Aresearcher lyses a cell that contains nucleic acid molecules and capsomeres of tobacco mosaic virus (tmv). the cell contents are left in a covered test tube overnight. the next day this mixture is sprayed on tobacco plants. we expect that the plants would ) develop some but not all of the symptoms of the tmv infectionb) develop the typical symptoms of tmv infectionc) not show any disease symptomsd) become infected, but the sap from these plants would be unable to infect other plants