英语书面表达：Sarah今年夏天计划来中国旅游，李明写信欢迎她来中国，并向她咨询到达和停留的时间国

Dear Sarah,
Thank you for your letter and wishes, and from that i have gotten that you are planning to come and visit China in this summer.
At first i should say welcome to your coming, and hope you will have a good time here. Then allow me to ask the time you will arrive and how long you will stay here.
Looking forward your return and best wishes!~

Yours sincerely,
Shen