In 2004，the World Health Organization，WHO，warned of a possible outbreak of another serious disease which may be even more deadly than SARS．The WHO believes that it is likely that bird flu will spread to human beings in the next few years．If it does，up to seven millions people could die from the disease．
Diseases like bird flu are caused by viruses，that is，tiny things which change and become more dangerous over time．When a new type of a common virus changes，it may be able to get past the body’s immune(免疫的)system．If that happens，humans are in great danger until a cure or treatment becomes available．
There have always been viruses and people always get sick，of course，but as we saw with SARS，the situation is more difficult today．People travel more than ever before，which means that disease can spread quickly and across large areas——in fact the whole world．
Scientists are already working on drugs that will prevent or limit the effect of a new virus，but the process takes time．It is just as important to make sure that countries，especially poor countries，are prepared to deal with the disease. New disease usually affect poor areas the most，so we must help develop health care in all countries．
The situation is more serious today because ．
A．people travel more B．people don’t eat healthy food
C．there aren’t enough hospitals D．scientists can’t find a cure
From this passage we know ．
A．bird flu will surely spread to human beings in the next few years．
B．a virus changes and become less dangerous over time．
C．SARS is 1ikely to come again in some years．
D．poor areas usually suffers more from new diseases than rich areas．
The possible title of this passage is
A．The Work of WHO
B．Scientists Are Working Hard on Drugs for Diseases
C．What Is a Virus
D．Virus Changes and Causes New Diseases Over Time