In an experimental investigation, the variable that the researcher changes or manipulates in order to see its effects is called the variable.

Independent just took test

Explanation:

the  seven  days  battles  were  a series of seven battles over seven  days from june 25 to july 1, 1862, near richmond, virginia,  during  the american civil war. the  seven  days ended with mcclellan's army in relative safety next to the james river, having suffered almost 16,000 casualtiesduring  the retreat.

"the attempts of the proletariat to rise above this abasement"