I think it refers to worldwide mutual dependence between nations/countries as we depend on each other for the key things like food etc. on a worldwide level.
1772 miles from the equator
Primary economic activities are defined as extracting raw materials. This includes mining, arable and pastoral farming, forestry and fishing.
Secondary economic activities include manufacturing good using raw materials. An example could be anything made in a factory, such as cars or processed foods, to a house or roads.
Tertiary economic activities provide services and good to people. Teachers, shops and doctors provide tertiary economic activities.
1. Declines in primary sector employment
Machines take away the need for manual labor in the primary economic sector.
As there is often higher paid jobs in the tertiary economic sector people begin to get an education and aim for jobs in the tertiary sector instead.
2. Decreases in infant mortality rate
Education of basic health care helps communities give a child a healthy environment growing up.
More availability of medical resources and professionals help to treat the illnesses that could cause the death of an infant.
3. Improvements in women's social status
Higher education for both women and men encourages gender equality.
Women become less dependent on men with more education and can gain better jobs and equal social status.
Answer:
volcanic outgassing - carbon dioxcide
comets and meteoroids - icy debris
major component of modern atmosphere - nitrogen
