supply and demand

I used to think that economics is merely about supply and demand. After taking the economics course in the Junior years, I found that indeed it is. However,one difference is that economics is not only "merely" about supply and demand, but it's based on supply and demand. They are the essential elements of economics and are everywhere. This afternoon I just read a news about the rabies problem in Taiwan. With the widespread of rabies, many people took their pets and themselves to inject vaccine. Then here comes the problem --soon there is a shortage in vaccine. What's even worse is that there are only 3 bottles of human rabies immunoglobulin (HRIG, the treatment for rabies) left in Taiwan. The soonest time to import more bottles HRIG will be on 7/29. With the increasing demand, the supply rises sharply. This is only one tiny example of supply and demand in our life. I wish taking the AP Economics course can help me to develop more economic topic and knowledge.