State, country, regime

Sapitientia's definition is unclear, btw he should answer in English.

State: You can refer to souverign body as a state(國家), particularly
when you are discussing politics. Examples are US, Israel, Japan..etc
Some large countries such as the USA are divided into smaller areas
called states. ( Washington State)

Country (國土): is it the territory of a state. Hong Kong is not a
country, is it China, just a SAR. An example of a country would be
America which belongs to the United States, England which belongs
to United Kingdom, China which belongs to People's Republic of
China.

Regime: It is the government body in charge of the state. In US,
Obama's regime, in China, Hu Jintao or CCP's regime. China is not a communist regime, although it is ruled by CCP. China is no longer a
communist country, it practices socialism (中國特色的社會主義), which is different to 共產主義.
It would be wrong to call China a Communist Regime.

以下是我的回答內容：
State是國度，即國家。中國和美國，是今天世上無人不曉的國家了。
Country是地區。如任何人仕，不知香港屬中國的特區。在出入境的表格上，填上香港在 Country下，就是了。
Regime是政權。有政治「岐視」之意。如一般的看法，今天的台灣，是一個民主的政權了；而中國大陸，有說是「共產」政權的表表者的呢！