A、<span style="font-size:14px;font-family:宋体">三角波</span><span style="font-size:14px;font-family:'Times New Roman','serif'"> </span>
B、<span style="font-size:14px;font-family:宋体">方波</span><span style="font-size:14px;font-family:'Times New Roman','serif'"> </span>
C、<span style="font-size:14px;font-family:宋体">梯形波</span><span style="font-size:14px;font-family:'Times New Roman','serif'"> </span>
D、<span style="font-size:14px;font-family:宋体">正弦波</span>