緊怎-AL Econ 90Q5

competition is the criteria for resources allocation. It decides who win and who lose.
you also have to give definition of 'monopoly', basically it is the sole provider of a goods and services, and it has no perfect substitute
but it still have to face competition (a) with close substitutes and (b) for inputs (factors of production e.g. raw materials etc)
壟斷即市場上的唯一供應者，例如從中環到羅湖的鐵路服務，便由「港鐵」壟斷。
但「港鐵」仍要面對競爭，例如你唔搭鐵路可以搭的士、巴士接駁，等等。