You can take as many books as you like here for they are free of .A. fareB. chargeC. money

问题补充：

You can take as many books as you like here for they are free of .

A. fare

B. charge

C. money

D. pay

答案：

A. fare

(答案→)B. charge

C. money

D. pay

解析：fare“运费、车费”； pay“工资、报酬”；charge“费用、收费”，free of charge意为“免费”。故选B。