HELP!!! TEST TOMORROW - I cannot copy text from ebook to fill in study guide

When I read through my ebook I cannot copy the text by using the edit icon, by right clicking nor by control c. Also, how do I remove the highlight from text I highlighted.  What is keeping me from being able to copy excerpts of the book I am reading on to a Microsoft Word document.  Please advise.  This program seems more difficult to use thank kindle reader.