An observational study is done to see if eating at least two apples a week helps prevent tooth decay in children. However, the researchers are aware that children who eat apples may also drink less soda, so they measure soda consumption as well. In this example, soda consumption is an example of

Soft drink consumption is an example of a controlled variable.

Explanation:

A very important type of variable in the execution of an experiment is the controlled variable. This type of variable is not directly part of the experiment, but it is inevitably present in the experiment and must be measured, since its existence has a direct importance in the research results. This can be seen in the research above, where one wants to evaluate the effects of apple feeding on the incidence of caries. The consumption of soda is not part of the experiment, but its existence can influence the result, so it is a controlled cariavel and must be measured.

the aksumite empire was an ancient kingdom located in what is now northern ethiopia from the period of 100 ad to 940 ad. its capital was the city of aksum. the kingdom established itself as one of the 4 great powers at its time, along with persia, rome, and china.

the kingdom was rich in goods like gold, iron, and salt. it established strong commercial ties with the regions governed by rome, egypt, and persia (arabia). aksum was a key location in this commercial network. trade was also facilitated with the introduction of the aksumite currency.

i only have part a but here is the first one: - lewis and clark are born

- lewis marries sacajawea and clark is jealous  

- clark drowns lewis and then goes to jail