1.用英语说欢迎回到学校怎么说:Welcome back to school.

2.老师向全班介绍新同学怎么说:Boys and girls,we have two new friends today.

3.用英语询问别人“你从哪里来”或“你来自哪里”怎么说:Where are you from?

4.用英语回答“我来自哪里”怎么说:I'm from the ukChinaUSA……