When you knock on a door, what causes you to hear a sound?

what is the answer

An economic system where all or most businesses are owned by government

Troy is the ceo of a manufacturing company, and he is planning to open a new factory in his community. because the new factory will require heavier traffic from delivery trucks and employees' cars, troy is partnering with the city to expand and rebuild roadways in the neighborhood. as part of opening the factory, he also plans to create a new hiring program. because he wants his workers to gain skills, he will also offer them the opportunity to attend college courses to receive business training. which of these outcomes are possible negative externalities? check all that apply. increased traffic in the neighborhood surrounding the factory better roads for drivers in the area more educated workers in the community pollution from trucks making deliveries to the factory new job opportunities in the city

Toward the end of the roman empire, what caused a decrease in the use of coined money tell me now