商务英语中的商务邮件写作当中的结束:"look forward to & looking forward to"哪个是正式用法哪个非正式?

问题描述:

商务英语中的商务邮件写作当中的结束:"look forward to & looking forward to"哪个是正式用法哪个非正式?
I look forward to hearing from you soon 和 I'm looking forward to hearing from you soon.这两个哪个是formal用法,哪个是informal用法?

在商务邮件写作中,结尾通常采用
I look forward to hearing from you soon.
或者是 I look forward to your reply .