what word links these: battery, rain, test?

Questions

Southpark: what are there a lot of in china, according to mrs. Cartman?

Southpark: what is printed on chef's apron?

Southpark: what is the name of the newspaper mr garrison is reading at the quarry?

Southpark: what letter is on everyones shirt at the canadian football game:?

Southpark: what will you clean to support your drug habits if you fail the 3rd grade?