1 There are two types of glial cells in the nervous system: the large-bodied macroglia and the smaller microglia. 2  There are two classes of macroglia in the central nervous system: astrocytes and oligodendrocytes.
Exports directly contribute and imports directly reduce their nation's balance of trade (i.e. net exports). A trade surplus is positive net balance of trade, and a trade deficit is a negative net balance of trade.
A trade-off is a situational decision that involves diminishing or losing one quality, quantity or property of a set or design in return for gains in other aspects. In simple terms, a tradeoff is where one thing increases and another must decrease. Tradeoffs stem from limitations of many origins, including simple physics - for instance, only a certain volume of objects can fit into a given space, so a full container must remove some items in order to accept any more, and vessels can carry a few