Today in the development, found that the home page can not add other parameters!

Desired results:
http://domain/?aaa=1
http://domain/?aaa=1&start=10
http://domain/?aaa=1&start=20

The result of the present:
http://domain/?aaa=1
http://domain/?start=10
http://domain/?start=20

Should it be like this?

The above content for software translation!