This is how you can allow others to view a file in your dropbox. They are not required to have a dropbox account to view the file you share with them. See these instructions if you would like someone to collaborate on file with you.
1. Sign in to dropbox.com.
2. Click All files in the left sidebar.
3. Navigate to the file or folder you'd like to share, hover over and click Share icon (person).
4. If a link hasn't been created, click Create. OR If a link was already created, click Copy link.
5. The link will be copied to your clipboard. You can then paste it to an email, message, or add to a course site resources such as a URL.
Additional Instructions on how to share a file from Dropbox
To disable downloads for a shared link on dropbox.com:
Additional Permissions Controls from Dropbox