History teaches that the influenza virus mutates to cause worldwide spread about twice a century , on average .
历史教训,流感病毒变异引起世界传播大约一个世纪平均两次。
If tb isn 't attacked with the right medicines long enough to kill it , the bacteria mutates .
患者若没有服用足够长时间的适当药物来杀死结核菌,它就会发生变异。
If the shell mutates , the honeycomb won 't lock together , and the virus would collapse .
如果病毒壳变异,蜂窝结构就会解锁,病毒随之解体。
That is because flu mutates , so catching it one year may not stop you from catching it the next .
这是因为流感会变异,今年得过流感并不会防止你明年再得。
The model also showed that once those t cells are released into the bloodstream , they can effectively attack hiv proteins , even when the virus mutates .
这个模型显示,一旦t细胞释放入血,它们就可以强烈攻击hiv蛋白,即使它们已经变异了。
Knowing that all four strains were at least 10000 years old , scientists recalculated the virus 's " molecular clock , " measuring how fast it mutates .
知道了这四个种族已经有至少一万年历史,科学家重新计算了病毒的“分子钟”,测量病毒的变异速度。
Last year , the indonesians stopped giving the who samples of the h5 virus which is responsible for avian flu , a disease that has forced a mass slaughter of poultry in many countries and could , if it mutates , cause a deadly epidemic among humans .