Vertical integration happens when one company controls all aspects of its production process. 

Hong Kong, South Korea, Taiwan, and Singapore are all considered Asian Tigers. The Four Asian Tigers are countries in East and Southeast Asia that experienced rapid growth between 1960 and 1990. Japan experienced its growth before World War II, making it a world power by the 1930s.

“Bulk-gaining industries” are so named because they make products that weigh more after they are assembled from their composite parts than they weigh before they are assembled. For “bulk-reducing industries” the opposite is true - their products weigh less after assembly. Because it costs more to transport something the heavier it is (as a general rule) “bulk-reducing industries” usually have their manufacturing centers close to the sources of raw materials, whereas “bulk-gaining industries” usually have their manufacturing centers close to the source of various large markets.

Secondary economic activities include anything that involves the assembly of raw materials. Manufacturing constitutes the majority of what could be considered a secondary economic activity. It is currently the biggest part of the economy in much of the semi-developed world.

A “break-bulk point” is the name given to an economic center, like a dockyard, where a manufactured product is assembled and then separated into various shipments ready to be transported to a wide range of markets.

Quinary economic activities are sometimes considered as a subset of quaternary economic activities. Other times, they are considered to be an independent group of economic activity. Quinary economics are separate from quaternary because they use collaborative research projects, data analysis, and scientific inquiry designed to improve policy-making of governments and decision-making of corporations. It is an extremely modern branch of economic activity and one that is still being defined.

Quaternary economic activities include anything that has to do with research, teaching, and development. Other examples include computer and information work, consultancy, and scientific inquiry.  

Despite having the world’s second largest economy, China is not considered one of the “core” countries in the Core-Periphery Model. This is because standards of living and levels of product consumption are still quite low for a large majority of Chinese citizens. China’s economy is heavily driven by its manufacturing and exporting, which is a characteristic of a “semi-peripheral” country.

Tertiary economic activities are associated with the sale and exchange of manufactured products and raw materials. Examples of this include retail and marketing. In the past hundred years the majority of people living in the developed world have become associated with tertiary economic activities.

“World Cities” are so-named because they are global centers of economic activity. They are generally also centers of cultural diffusion and are extremely diverse, but this is not what makes them “World Cities.” Many are capital cities of major economic countries, but many are not, such as New York City and Los Angeles. the key to this question was narrowing the possibilities down to the most specific, and most significant, reason for the appellation.