The broader effect of a society's production levels and monetary support is included for non-working citizens.
Historically, conquerors have been made rich through plunder, access to new resources and enlarged trade.
Multi-national agreements, mutual inter-dependence and availability of natural resources will characterize today's complex system of international trade.
A key determinant of international relations has proposed economic security.
Everyone believes that there is a tradeoff between economic security and economic opportunity.
Объяснение:
Have to - должен (по внешним обстоятельствам, например ты должен заплатить на книгу)
Can - мочь что-то (я могу починить ящик - например)
Could - по значению как и Can, но используется чаще при вежливом обращении (не могли бы Вы мне например)