Several Chinese language tutors in Singapore publish free weekly answers to common workbooks. Examples:
Finding free answers is easy. Using them wisely is the real skill. huo dong ben answers sec 3 free
Some tutors now video-solve Huo Dong Ben pages. Search: Several Chinese language tutors in Singapore publish free
If one search fails, try these. Bookmark this list: Pro tip: Add filetype:pdf to your Google search
Pro tip: Add filetype:pdf to your Google search to get direct download links.