"Speech is the most highly skilled muscular activity that human beings ever achieve,requiring the precise and rapid coordination of more than eighty different muscles ,many of them paired
You can't just throw us a sentence and say, 'Hey! What does it mean?' You need to be specific. Breaking down a long sentence is also a part of learning process. I am pretty sure there is something you do understand in this sentence. After you do that, you tell us first what you do understand and we will help you with what you don't.