A food additive is any substance that is added to food. Many people are put off by the idea of “chemicals in food”. The truth is that all food is made up of chemicals. Natural substances like milk, as well as man-made ones like drinks on sale in the market, can be described by chemical formulas. Some chemical substances are indeed harmful, but a person who refuses to consume any chemicals would find nothing to eat.

The things we eat can be divided into natural and man-made substances. Some people feel that only natural foods are healthy and that all man-made ingredients are to be eliminated. But many natural chemicals, found in plants and animals, are harmful when eaten, and some laboratory-made substances increase the nutritional value of food. Other chemicals have natural and man-made forms that are exactly alike: vitamin C is vitamin C, whether it comes from a test tube or from an orange.

Later, the Ming Dynasty     1     developed relations with these regions. Between 1405 and 1433, seven large fleets sailed west on voyages of trade and exploration. These fleets were a sight to behold and were in a     2     of their own at that time. …African     3     families sent gifts such as giraffes as gestures of friendship in return for gold, silk, and spices. Although China     4     from further expeditions after 1433, these land and sea routes remained active     5     between other, cultures for centuries.