PLEASE ANSWER FAST!! How did terraces improve Chinese agriculture?

A. Sped up plowing and sowing of fields
B. Created more farmland for raising crops
C. Made it easier to harvest grain and other crops
D. Simplified the process of cleaning seeds from plant fibers

Which of the following world and national events led to a new view of people with disabilities in the us:     a.  world war i and ii veterans with disabilities returned home after the wars. b.  john f. kennedy was elected president and had a sister with a disability. c.  the civil rights and feminist movements. d.  all of the above.