If you buy one,you can get another free of c___(缺词填空）

If you buy one,you can get another free of c___(缺词填空）
If you buy one,you can get another free of c___(缺词填空）

If you buy one,you can get another free of c___(缺词填空）
charge收费的意思,free of charge意思是免费

charge

buy one with a free one buy one present one. 参考一下吧，应该或者You can get another one if you buy one of them Buy one and