如何将预付费用户更改为后付费用户？我是预付费用户，我不擅长英语，但预付费用户无法从在线专家那里获得帮助，我很沮丧
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如何将预付费用户更改为后付费用户？我是预付费用户，我不擅长英语，但预付费用户无法从在线专家那里获得帮助，我很沮丧
Enter your username or e-mail address. We'll send you an e-mail with instructions to reset your password.