When you are suspicious of the website, check it out () you pay any money.

科目名称：人文英语3

试卷号：11379

题型：词汇与结构(单选题)

题目：When you are suspicious of the website, check it out () you pay any money.

选项：1. before 2. after 3. until

需要1积分查看

答案：before