15.8 COMMUNICATION LABORATORY
A.Give a brief answer to the following questions.
（1）What are public signs？
（2）What are the functions of public signs？
（3）What are the differences between public signs and notices？
B.Case Study
（1）Improve the public signs listed below.
a.Please only put toilet tissue down the toilet.
b.Business Suspended
c.No dogs bikes skates skateboarding.(https://www.daowen.com)
d.Rope Way Station
（2）Write some public signs based on the following situations.Use figures or pictures
to clarify the public signs when necessary.
a.It is dangerous for passengers to get on the train with things that are easy to catch fire.
b.We have some guests here and please don't make any noise.
c.Warn people that it is a route leading to nowhere.
d.Warn drivers to slow down because there is a kindergarten ahead.
（3）Try to find out some public signs that need improvement in China.