When you are free this afternoon,please help me to have these letters _.[A] to mail [B] mail [...

题目

When you are free this afternoon,please help me to have these letters _.[A] to mail [B] mail [...
When you are free this afternoon,please help me to have these letters _.[A] to mail [B] mail [C] mailed [D] mailing 这道题为什么选A呢?我选的B

答案

我觉得选C好些吧