In fact the house as well as his two cars him all the money he earned during the 20 year

问题补充：

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

答案：

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。