What's the correct verb to be used? [closed]
If the subject is considered as a unit or a single thing then we use "is".
If it is not considered as a unit or a single thing then we use "are".
In this case use of "having" makes it a single thing.
Having a suitable Tone, Pace and Volume ...
So "is" should be used here.
Example:
Having pen and pencil is important.
Pen and pencil are important.