Select all maintenance procedures that may be performed in an office. update software replace printer cartridges clean copy machines install virus-protection software print copies to be distributed at a meeting

update software and install virus protection software

Explanation:

Maintenance procedures that are performed in an office to ensure the smooth running of the office. updating software on the regular basis helps the office computer to be protected from the various malware threats your office computers might face and it helps maintain and prevent your computer from Virus and malware.

installing virus-protection software in your system is a very good step to protecting your system/office computer from malware.

Cleaning your copy machines helps the Machines to perform optimally and keeps it free from dust and rust. printing copies is not a maintenance procedures and replacing printer Cartridges is only done when neccessary i.e when the previous cartridge is bad. this is a repair procedure.  

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link :

answer; (15,000)workers each