Question

Over 80 percent of the population of China ______  peasants.

1. A.
   was
2. B.
   is
3. C.
   are
4. D.
   willbe

Answer 1

C
Over 80 percent of the population 做主语，谓语动词依据population 来定，population 指人谓语动词用复数，指“人口”用单数。