What might explain the changes in aerosol concentration as you gain altitudes

What effect did john hay’s open door policy letters have on the imperial powers of britain, france, germany, russia, and japan? a. it provoked the imperial powers to declare war on the united states. b. it caused the imperial powers to restrict trade in their trade with china. c. it warned the imperial powers that the united states would soon declare war on china. d. it signaled to those powers that the united states would take a larger role in world affairs than before.

When did the us congress declare war on the confederate states?

Brainliestttme : describe the following event: increase in islamic extremism in the middle east