【单选题】The farmers,___________houses had been destroyed by the serious flood,were given help by the government.
【单选题】As a result of the serious flood, two-thirds of the buildings in the area .
【判断题】相对于半波振子的天线增益用dBi表示。()
【简答题】Passage 6 The flood of migrants into Europe is it obvious that dialogue and agreement are necessary, to better protect the EU's external borders and reduce the pressure on affected countries. B...
【单选题】与全波振子天线相比,半波振子天线的工作频带( ),输入电阻( )。
【简答题】设以半波振子为接收天线,用来接收波长为λ、极化方向与振子平行的线极化平面波,试求其有效接收面积。
【简答题】基本半波振子的长度是(),而折合半波振子的总长为()。
【简答题】理想导电面上方水平放置的半波振子天线如图(a)所示。
【单选题】第一节 单项填空 从A、B、C、D四个选项中,选出可以填入空白处的最佳选项。 The flood did not start to ______ until two days after the rain had stopped.