matias may live farther away so its 0.7 kilometers.
jack may live closer to the bookstore so it may only be 0.5 kilometers.
Explanation:
Lack of infrastructure causes the cost of input in the medium scale industries to increase. For example, bad roads cause increased costs of transport and lack of cheaper electricity connectivity causes the industry to use expensive petroleum-based products for energy. Therefore, the medium scale industries will be unable to competitively set the price of their products to compete with large scale industries. Large scale industries can maint low prices due to their ability to manufacture large volumes of products hence enjoying economies of scale
I think it is gravity, because that's what holds together everything in the solar system, but you might want to check on that. XD
I believe T, hope this helps!