what is an example of variable overhead? $($CLO $3)$

what do you think are the reasons behind the differences in German and US cost accounting methodologies? $($CLO $3)$

What is the intention of cost accounting? $($CLO $3)$

How can accountants use cost accounting and provide the most useful information to managers? $($CLO $3)$

please cite the sources used to answer the question so i can verify. Thanks