What is this explaing someone let me know

How did the large influx of immigrants change america?

Why were the farmers not satisfied with only establishing cooperatives ?

Two technicians are discussing oil changes. technician a says that waste oil and old filters need to be disposed of according to the law. technician b says that old filters can be returned to the parts department for a core value. which technician is correct?           a. technician a only   b. both technicians a and b   c. technician b only   d. neither technician a nor b