can't convert pages to word

I wrote a very important school assignment a couple a weeks ago.

When I wrote it, I used a test version of Pages, I had it only for 30 days.

Now it's long ago, and I need the assignment again, but it lays as a pages file.

I have now microsoft word (there should be allowed to open pages files), but when I click on it, it says:

"The open XML file 'file name'.pages cannot be opened because there are problems with the contents

or the file name might contain invalid characters.

Details: The file is corrupt and cannot be opened."

Then I click OK, and this pops up:

"Word found unreadable content in 'file name'.pages.

Do you want to recover the contents of this document?

If you trust the source of this document, click yes."

Then I click Yes, and this pops up:

"The open XML file 'file name'.pages cannot be opened because there are problems with the contents

or the file name might contain invalid characters.

The file is corrupt and cannot be opened.

Details: Micosoft Office cannot open this file because some parts are missing or invalid."

CAN ANYONE PLS HELP ME OUT?

IT'S VERY IMPORTANT THAT I GET THIS FILE OPEN.

Thank you...