一简谐波的周期为T，图4-2为此波在t<img src="http://www.weimei168.com/uploads/202208/20120928144568556855.jpg" alt="" />的波形图．由图可知，此波（　　）<br /> <img src="http://www.weimei168.com/uploads/202208/20120928144597159715.jpg" alt="" /><br /> <img src="http://www.weimei168.com/uploads/202208/20120928144580068006.jpg" alt="" /><br /> <img src="http://www.weimei168.com/uploads/202208/20120928144587758775.jpg" alt="" /><br /> <img src="http://www.weimei168.com/uploads/202208/20120928144522582258.jpg" alt="" /><br /> <img src="http://www.weimei168.com/uploads/202208/20120928144552405240.jpg" alt="" /><br />