The USA, USA, The US, US

Hi,
The USA is right<<<we use the article when it is the place that composed of many small countries.For examle ,philippines,Bahamas(巴哈馬),Netherlands(荷蘭)

We need to add the before the United Kingdom .It is beacuse the united kingdom is composed of England,Wales,Scotland,Northern Ireland

When it just a country and des not compound of small countires such as,China,Hong Kong,lran etc
When it is ocean or continent(大洲) For example:Aisa, Europe,Africa
Ocean:artic ocean,indian ocean
Both WE USE the
明味

土地分散.由好多好多島組成ge國家/地方就要用the.簡單d就係甘.

If I remember it right, you need to add "The" before a country name if it is plural. So you need to add "The" before USA (United State"s"). UK and Europe, for example, are singular. So you don't need "The" before them.