In fact, the house as well as his two cars him all the money he earned during the 20 years．
A. has been cost
B. have cost
C. has cost
D. have been cost
网友回答
A. has been cost
B. have cost
(答案→)C. has cost
D. have been cost
解析：考查主谓一致。as well as连接两个部分做主语时，谓语动词要根据前一部分来判断，因此用单数；而sth cost sb money，因此不用被动。选C。