I often ask my English teacher some questions ( ) emails十分钟,

I often ask my English teacher some questions ( ) emails十分钟,
I often ask my English teacher some questions ( ) emails
十分钟,

I often ask my English teacher some questions ( ) emails十分钟,
I often ask my English teacher some questions (about) emails
我经常问英语老师一些关于邮件的问题.

答案是：by

by emails 通过邮件提问问题

望满意

with, 我经常用电子邮件问英语老师一些问题。