To be scientific useful, observations and experiments must

What type of speech was president reagan giving at brandenburg gate in west berlin

Which statement best evaluates the impact of the 1929 stock market crash on europe? 1. the united states established high export tariffs to europe that reduced goods exported to germany. 2. the united states promoted domestic policy initiates that reduced jobs on american bases in europe. 3. the united states promoted isolationism that withdrew troops from europe causing germany to pay its own national defense. 4. the united states eliminated loans to europe that caused germany to default on its reparation payments to france.

What is the main reason the united states removed the taliban from power shortly after the september 11 2001 attacks ?