In the objective below what is the independent and what is dependent variables?

"The objective of the study was to consider whether the association between maternal ACEs and child maltreatment is affected by three mediating factors: socio-economic status (SES), social support and maternal psychological distress in adulthood."

In the study there were also other variables they called "background variables". Background variables were included as covariates: maternal age, chi- ld's sex, grade, marital status, number of siblings and maternal child- hood SES.

I also need to know if these variables are are ordinal, interval, or ratio?

Once I figure out the dependent and independent variables I have to explain regression.

Thank you for any input you may be able to provide!