《针灸大成》的作者是
A．皇甫谧B．李时珍C．杨继洲D．徐凤E．滑寿
参考答案：C
选相元件是保证单相重合闸得以正常运用的重要环节，目前我国220kV电网中的选相逻辑在线路保护中实现。
—_____ the pants?
—They're 15 yuan. [ ]
A. How many is
B. How many are
C. How much is
D. How much are
