What was gunpower initially used for in China during the middle ages

What event brought the us into wwii? what conflicts happened after the us entered the war? i know the first part of this question, i need with the second part.

What happened as agriculture became entrenched in the south ?

:) during the cold war, people were afraid of communists, both outside and inside the united states. the red scare and mccarthyism that grew out of these fears were damaging to the american way of life. during the mccarthy years, many of the freedoms guaranteed in the bill of rights were limited. write a paragraph explaining what lessons can be learned from the mccarthy era about what u.s. citizens need to protect in order to preserve the democratic political system and the american way of life.