其实，人体就是一个活生生的例子。通常大家都认为细菌是有害的，孰不知人体如果没有了细菌，人是无法存活的。
IT IS GENERALLY BELIEVED THAT VIRUSES ARE HARMFUL, BUT SCARCELY DOES IT COME INTO OUR MIND THAT A PERSON CANNOT SURVIVE WITHOUT THEM.
其实，人体就是一个活生生的例子。通常大家都认为细菌是有害的，孰不知人体如果没有了细菌，人是无法存活的。
IT IS GENERALLY BELIEVED THAT VIRUSES ARE HARMFUL, BUT SCARCELY DOES IT COME INTO OUR MIND THAT A PERSON CANNOT SURVIVE WITHOUT THEM.
