Describe 2 geographical features of the Yellow River Valley.

Running and sleep. sufficient sleep is important for adolescents for both their neural and psychological development. despite this, daytıme sleepiness and poor physical and psychological functioning related to chronic sleep disturbances are common. there is a growing body of evidence that exercise is associated with both better sleep and improved psychological functioning sixty participants were recruited from a high school in northwesten switzerlandthey were randomly assigned to either a running group or a control group, 30 to each group the running group ran every moming for a little over 30 minutes on weekdays for a three-week period. all participants used a sleep log for subjective evaluation of sleep, and sleep was also objectively assessed at the beginning and end of the study using a sleep electroencephalographic device that measured quantities such as sleep efficiency and time spent in the four different sleep phases. running was found to have a positive impact on both objective and subjective measures of sleep functioning what are the explanatory variable(s) and the response variable(s)? (a) outline the design of the experiment (b) (c) here are some more details on the treatment and control groups. all participants arrived at school at 7 a. m., and the running group did two laps on the track and then ran cross countrv in groups of at least four people for 30 minutes the control group remained seated at the track, worked on horpework. and interacted with each other. when the runners returned, all participants prepared for school and ate a breaktast that was provided. iwhy do you think the experimenters had the control group arrive at 7 am interact withdassmates and have breaktast together? explain. do you think having the control eroup do these activities is important for the types of conclusion that can be reached? how?

1of the following choices, which one best describes one way that christianity came to east africa? a. christians traveled in caravans through the sahara desert and introduced the people of mali to a new religion. b. christian traders from the mediterranean interacted with the people of axum. c. christian military from west africa traveled across the continent to bring their religion to the people of east africa. d. christian rulers from asia traveled to east africa to bring their religion to the people. 2 which trade item from outside the region did west africans need most? a. gold b. camels c. salt d. iron

Which of the following selections is least useful for supporting the claim that states intentionally built unequal school systems? question 1 options: the supreme court ruling in plessy v. ferguson (1896) wrote into law that america had two separate societies: one black and one white. it was very clear by the mid-1900s that southern states had expertly built separate educational systems. these schools, however, were never equal. states with laws keeping schools segregated never gave equal amounts of money to their black and white schools. ten years after brown, fewer than 10 percent of southern public schools had integrated. some areas did not comply at all.