什么是分裂导线？
参考答案：
分裂导线就是每相导线由两根或两根以上同型号的导线组成。它是发展超高压输电中，出现的一种新布线方式。
—Where is my pen?
—I _________ it on the desk, but I don’t know who _________ it away.
A．put; has taken
B．put; took
C．have put; took
D．have put; has taken
排污时，排污管道发现有冲击声时如何处理？
