2010年2月28日上午9点10分，“两岸四地共希望”希望一号卫星青少年业余无线电通信活动正式开始．作为主会场的南京某中学业余电台BY4RRR顺利的与北京、台北、广州分会场进行了通联，表达了各自元宵佳节的祝福．传递他们之间的通话信息是利用（ ）
A．超声波
B．电磁波
C．次声波
D．可见光
无线电通信是利用电磁波为载体传递声音和图象的．
故选B．
We kids have different ways to get in touch(接触) with each other now. And for the old, they’d like to go to the market or each other’s houses, but for the young, we kids needn’t follow the of doing so. The easiest way for us to get in touch and make is to use the Internet services, like QQ. A lot of websites such as www.qq.com have in the last few years and offered such kinds of for free. So we can make friends through the Internet. Maybe we do not all these “friend” well. We add friends only we seem cooler with more friends online. Then how do we kids keep in touch with friends online? We make it by posting our to each other. At times , “friends” “be missing” for months without a message. Is this the friendship in the 21st century? Of course, using these Internet services is not for saying “ Hi, what’s up?” Some of us have found long-lost classmates and friends these websites. And at times we a time to go to a movie or get together. What’s more, we kids can our friends’ favorite music when we are on the Internet. Believe it or not, these Internet services will be for a while, and it is really a convenient way for us to keep in touch. |