Worksheet function: How to intersperse rows of data in Google Sheets or Excel?

I have data in several different worksheets and I want to combine it into a single sheet. The data is text, not numeric. I can do this work in Google Sheets or in Excel.
I have:

Sheet1 R1

Sheet1 R2

Sheet2 R1

Sheet2 R2

I want to consolidate this in worksheet 3:

Sheet1 R1

Sheet2 R1

Sheet1 R2

Sheet2 R2