Question

why would you need to purge a cylinder? select all that apply. the cylinder was not purged by the manufacturer. the cylinder was opened to the atmosphere. the cylinder still has some propane in it.

Explanation:

When a cylinder was not purged by the manufacturer, it may contain contaminants or unwanted gases. If it was opened to the atmosphere, air and other substances could have entered. Purging is to remove such impurities. Having some propane left is not a reason for purging in the context of removing contaminants or unwanted substances from the cylinder.

Answer:

The cylinder was not purged by the manufacturer.
The cylinder was opened to the atmosphere.