Norman thinks that the brain function of students suffers when they receive less sleep. He predicts that students who get less sleep before an exam will receive lower test grades. To investigate his idea, he tests two groups of chemistry students. Group 1 receives four hours of sleep, while Group 2 receives the recommended eight hours of sleep the night before the exam. Both groups consume the same foods before testing. They then take the same exam in the same room. What experimental factors could have been a possible source of error in Norman's investigation? A. the food students consumed before the exam
B. the amount of sleep students received before the exam
C. the grades students earned on their exam
D. the temperature and light of the testing room

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

the apgar score is 6

here are the 5 factors that are observed when calculating the apgar index:

skin color

blue everywhere - 0 points

white on the ends and pink on the body - 1 point

all pink - 2 points

heartbeat

absent - 0 points

slow - 1 point

fast - 2 points

reflexes

no answer: 0 points

responds to stimulations: 1 point

cries and coughs: 2 points

muscle tone

soft: 0 point

some bending or stretching: 1 point

active movements: 2 points

breathing

absent: 0 points

weak or irregular: 1 point

good and your baby is crying: 2 points

it is estimated that children whose score is between 8 and 10 are in perfect health and need only routine care. a score between 5 and 7 is representative of a fair condition. often this means that the child has suffered during delivery and probably needs with breathing. as a first step, your doctor will carefully rub the skin of your baby or give him oxygen with a mask.