-- of the population of the city workers?
--About 60 percent.
A. What; is
B. What; are
C. How much; is
D. How much; are
网友回答
A. What; is
B. What; are
C. How much; is
(答案→)D. How much; are
解析：考查population的用法。对人口“提问”，用what来问总人口；how much问的是“多少（比例）”。句意“这个城市人口的多少比例是工人？”“大约60%。”population作主语，谓语用单数，但是指具体的人数时，谓语用复数。故选D。