—How much if I wan to take one?—You can take as many as you like because they are free of

问题补充：

—How much if I wan to take one?

—You can take as many as you like because they are free of .

A. cost

B. charge

C. money

D. pay

答案：

A. cost

B. charge

C. money

D. pay

解析： free of charge “免费”是固定短语。