Scientists are creating vaccinations that prevent people from getting bird flu. If the virus mutates, a new vaccine needs to be made. The vaccine needs to be tested, which can be dangerous. It also takes a long time for scientists to know whether the vaccine works.
<span>Which is an example of a sport that has low equipment costs?
</span><span>-The Nordic walking
-the yoga
-gymnastics
-swimming</span>
1, 2& 4th bullet I think is correct
