New flu vaccines need to be made each season because the viruses are constantly changing so as to avoid attack by host immune defences - whether in birds, humans or other animals.

每个季度都要制造新的流感疫苗是因为流感病毒会不断地变化从而逃避宿主(无论是人类、鸟类还是其他动物)免疫防线的攻击。

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The chemicals that damage fungi tend to damage human cells as well, so it's hard to attack such infections without harming the host.

能够破坏真菌的化学物质也倾向于损害人类细胞，所以很难在不伤害宿主的情况下消除这种感染。

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They can be used to attack other systems, host attack tools, send spam, or just steal data.

犯罪分子可以利用计算机网络攻击他人计算机系统、软件、发送垃圾邮件或是窃取资料。

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The attack comes as Rio prepares to host next year's World Cup final and the 2016 Summer Olympics.

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In a web-based attack scenario, an attacker would have to host a website that contains a specially crafted web page that is used to exploit this vulnerability.

FORBES: Connect

The attack comes as Rio, a former hotbed of crime that had become safer in recent years, prepares to host next year's World Cup final and the 2016 Summer Olympics.

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