When researchers manipulate a variable in a study, they are carrying out a(n) – . The manipulated variable is often called the – variable. A manipulated variable always has more than one level, or – . Researchers measure the – variable to determine the effect of the manipulated variable on it. Researchers often keep certain other factors constant on purpose. This kind of variable is called a(n) – variable.

after balancing the chemical equation, what are the coefficients for these compounds?

h2s      

⇒ 3

hno3    

⇒ 2

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the period of human evolution has coincided with environmental change, including ('hominin' refers to any bipedal species closely related to humans – that is, on how do we know earth's climate has changed? a map showing dates and locations of prehistoric archeological sites and migration routes from africa into.