为什么发射台要将信息调制到高频载波上再发送？
参考答案：1）信号不调制进行发射天线太长，无法架设。
2）信号不调制进行传播会相互干扰，无法接收。
Speaker A: Congratulations! I hope you'll be very happy.Speaker B: ______
A．Thanks, the same to you.
B．Thanks, I'm sure we will.
C．Yes, that's for sure.
D．Yes. I am sure we'll be the happiest couple in the world.
当归用于补血，宜用
A．当归头B．当归身C．当归尾D．全当归E．当归须
