A dairy farmer wanted to increase the amount of milk produced by his cows. He decides to test the effect of a particular feed additive. He give half of his herd
the additive. He maintains the amount of grazing time, the amount of water the
cows drink per day, and even how often the cow gets chased by the local dog
was the same for all the cows. Each day the farmer milks the cows at the same
time and compares the volume of milk. What is the independent variable?

The intervention of extraterrestrials has been used to explain the bermuda triangle, a region of the atlantic ocean where ships and planes are frequently lost, leaving no evidence behind. how would this explanation best be characterized?

1. emigration the movement of people from one place to another 2. immigration a situation in which resources are being used up at a faster rate than they can be replenished 3. migration the leaving of one's homeland to settle in a new place 4. overpopulation the movement of people to a new country 5. sustainable development a situation in which the birth rate is not sufficient to replace the existing population 6. underpopulation the ability to meet current needs without reducing the ability to meet future needs 7. unsustainable development the increase in the population of a city 8. urbanization a situation in which the number of people exceeds the available natural resources in an area

Natural resources are any materials that humans obtain from the earth to meet our wants and needs.