When I translate, what happens is that the source sentence remains in the WordDoc. Surprisingly, what happens in the tutorial section is that the source sentence is removed after clicking on the bottom of "set/close" to finish the translation. With me the source sentence is not removed so when I finish the work I get both source sentence and target sentences together. In reality, just target sentences must remain.
Please review the entire workflow - "cleaning up" (= removing source segments from the document) is the last step. Source and target remain in the (bilingual) document during editing. You can make the source text invisible by hiding hidden text; however, given the danger of damaging tags, it is recommended to keep both source and target visible during translation.