The nondescript bacteria were responsible for the infectivity of the filtrate.是什么意思？

The nondescript bacteria were responsible for the infectivity of the filtrate.

这种滤液的侵染性应归之于不能描述的细菌.

the

art. 指已提到的人（物），指说话人与听者已知的人（物），用于独一无二的事物前，与形容词最高级和序数词连用；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

nondescript

--

例句
Europa House is one of those hundreds of nondescript buildings along the Bath Road.
欧罗巴大楼是巴斯大道沿路那些成百上千幢毫无特色的建筑之一。

bacteria

n. 细菌(bacterium的名词复数)；

例句
Exactly which bacteria cause the infection is still unknown.
到底是什么细菌引起的感染还不清楚。

were

be的过去时复数和第二人称单数形式，有时代替 was,用于条件从句、动词 wish 之后等；

例句
Shops, houses, and vehicles were set ablaze.
店铺、房子和车辆全都陷于火海。

responsible

adj. 尽责的，承担责任，负有责任的，懂道理的；

例句
It is accepted wisdom that science has been partly responsible for the decline of religion.
人们普遍认为，科学的兴起是宗教衰落的部分原因。

for

prep. 为，为了，倾向于，关于，当作；conj. 因为，由于；

例句
I've come looking for a bit of advice.
我特来讨教。

infectivity

n. 传染性，易传染，感染性；

例句
The nondescript bacteria were responsible for the infectivity of the filtrate.
这种滤液的侵染性应归之于不能描述的细菌.

of

prep. 关于，属于…的，由…制成；aux. 助动词 [非标准用语、方言] =have [主用于虚拟语气]；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

filtrate

v. 过滤，筛选；n. 滤出液；

例句
Objective To observe the effect of filtrate of normal human fresh dejecta on intestinal flora alteration.
目的观察正常人新鲜粪便滤液治疗肠道菌群失调的疗效.