Hello.<br/><br/> What is the difference in meaning between these sentences?<br/><br/> - The birds <font color="Red">flew</font> the trees.<br/> - The birds <font color="Red">flew up </font>the trees.<br/> - The birds <font color="Red">flew up over</font> the trees.<br/><br/> I would be grateful for your help about this thread.