On the advantages and disadvantages of ancient methods of transmitting information.

1, the post office is riding a horse to deliver letters. The post station is equivalent to the present station. The advantage of slow speed, labor saving and money saving is accurate news ~

2. Pigeons are unreliable. There is no guarantee that the delivery task can be completed on time and with good quality. The advantage is that if it is delivered, the speed should be good ~

3. The beacon tower is the number and location of smoke caused by fire on the beacon tower. The advantage of delivering messages is that it is fast. The speed of light propagation is multiple. The disadvantage is that the scope of application is small, which is probably invisible beyond the mountain ~