ANSWER IS C HOPE IT HELPS :D
To be able to compare the results to a sample without any of the independent variable added.
8: this model is similar to a real life model because it shows what you can have in and around your house
9: the way this model can be useful is by helping show how to build your house the way you want it to be and what you would want
A theory which is tested again and again and found to fit the facts and from the valid predictions may be made is then known as scientif ic law or priciples..