Answer:- "Since most teenagers still lived at home, they could afford to work for wages too low to support an adult, and until recently, their limited skills attracted few other employers".
Explanation:
The author("Eric Schlosser") in "Fast Food Nation" felt that teenagers are the perfect applicants for working in the fast-food industry as they mostly stayed at home and usually work at inadequate payment as per their potential. Author substantiates his claim by offering above mentioned statement that 'since...adult until' recently the skills of the teenagers have been recognized by few employers as they felt teenagers are full of energy, vigor, and potential that may lead to producing exceptional outcomes especially in fast food industry as they would be able to understand the choices and preferences of the consumers who are mostly teenagers and work more diligently and efficiently as compared to other age groups.