【单选题】无线电波有四种,分别是中波、短波、超短波和微波.其中关于微波叙述正确的是( ).
A.
沿地面传播,绕射能力强,适用于广播和海上通信
C.
具有极高频率的电磁波,波长很短,主要是直线传播,也可以从物体上得到反射
D.
和超短波一样饶射能力都很好,但不可作为视距或超视距中继通信
【单选题】Please choose the more formal one.
【简答题】根据文章内容,判断下列句子正(T) 误 (F)。 It's different between western countries and eastern countries about how to keep healthy. Traditional Chinese doctors believe we need a balance of cool yin and hot yang to be ...
【简答题】阅读理解。 There're five people at our table, including myself. I've already learnt a great deal about them in the short time we've been at sea, although we rarely meet except at meal times. First of all, ...
【单选题】Please choose the proper one to describe the picture .
【单选题】Please choose the more formal one.
【简答题】无线电波有四种,分别是中波、短波、超短波和微波.其中关于微波叙述正确的是().A. 沿地面传播,绕射能力强,适用于广播和海上通信 B. 具有较强的电离层反射能力,适用于环球通信 C. 具有极高频率的电磁波,波长很短,主要是直线传播,也可以从物体上得到反 D. 和超短波一样饶射能力都很好,但不可作为视距或超视距