3. Which country is an example of a presidential democracy? a. United States

b. Brazil

c. Mexico

d. All of the above

d. All of the above

Explanation:

The United States is the originator and primary example of the presidential system, a model that is followed in only a few other democracies, such as Argentina, Brazil, Mexico, and the Philippines.

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answer; earthquake;

productive most commonly means: achieving or producing a significant amount or result.

explanation:

productive can also mean:

these depend on how the word productive is used. most likely productive will mean   achieving or producing a significant amount or result.