Why was the open door policy promoted by the united states

In 1990, the average income for an american worker was $1,518 per month. in 2000, the average income for an american worker was $2,632 per month. during this time period, a basket of necessities (food, housing, etc.) increased from $657 per month in 1990 to $1,402 per month in 2000. the real value of income ▼ increased decreased over that 10-year period.

What does it mean to say that "service sector" jobs are predominant in europe's mixed economies today? a. that jobs where people work in factories predominate b. that jobs where people do something for others predominate c. that jobs where people work the land predominate d. that jobs in government predominate

Why are people in history willing to fight in conflicts against a more powerful oppressor?