问题描述：
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
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
问题解答：
我来补答展开全文阅读