what was new technology used during World War II, helped keep soldiers and civilians healthy. Multiple Choice is down below:)!!

In some african american communities, unemployment was as high as percent.

In an industry in which there are several providers of a type of good, why can one business not charge much higher prices for their goods?

Which of the following is/are a major technological advances of the mayan civilization? a. the calendar c. math b. architecture d. all of the above