$4-$On page $130$ line $17$ onwards our author states $"$ It should be stressed that government$-$supported insurance schemes through national export credit agencies $($ECAs or just agencies$)$ areestablished in only about $40$ industrialized or emerging market countries $($see separate box later in this chapter$),$ even though this covers a large part of total world trade. However, the role of the agencies and the cover they may give to promote exports from these countries are also of great importance to buyers in most countries, since they fulfil an important role in supporting the transfer of goods and services and, indirectly, provide knowledge and expertise to many countries, particularly developing countries; in many cases this would not have happened without this support."a$)$what does the above paragraph imply about the "goods" covered by such export credits?b$)$What is the connection, if any, between such trade and "providing knowledge and expertise to many countries"?