When you rehearse a presentation, you should

a$.$keep your volume steady so that every listener can hear you throughout the presentation.

b$.$concentrate on what you want to say, not on how you say it$.$

c$.$simulate the conditions of the meeting room as closely as possible.

d$.$practice two$-$handed gestures for emphasis.

e$.$practice four or more times with an audience so that you can obtain detailed feedback for improvement.