Beginning of Essay
Do you know how many chickens do we consume every day? Three thousand, five thousand or more? We demand almost more than ten thousand chickens daily. What a big figure! We can see that chickens are very important to Chinese society. Chickens are always devoted to ....

Middle of Essay
.... as this is the type of virus that has caused world-wide pandemics. And H5N1 belongs to the vision of influenza A. What is H5N1? H stands for hemagglutinin (HA), which is a viral protein. It will cause the red blood cells to stick together. And N is the viral protein too, which is called neuraminidase (NA). In an influenza virion, there are five hundred spikes sticking out from its lipid envelope in which 80% of the spikes are HA and 20% NA. HA helps the virion get into host cells and NA helps the offspring virions to get out. The two virions together are responsible for the viruses¡¦ability to cause the disease. (Cited from http://www.synaps ....