晶闸管主要有哪些优点。
参考答案：晶闸管的优点是：晶闸管具有体积小、重量轻、效率高、控制使用方便、无噪声等优点。
I ______ along the road when I saw Peter. So we stopped and had a chat.
A．walked
B．was walking
C．would walk
D．had walked
高位颈髓瘫痪特点
