These holes let water slowly pass through the walls of the filter.

VOA: special.2009.06.22

And there's two parts of the filter.

这个过滤器由两部分组成。

麻省理工公开课 - 化学原理课程节选

What all of these channels have is what's called a selectivity filter, so this filter filters out the type of ion that's going to be allowed through.

这些离子通道都有的一部分,就是所谓的选择性过滤器，这个过滤器,会滤过允许穿过的离子。

麻省理工公开课 - 化学原理课程节选

Tests have shown that the filter produces safe drinking water.

VOA: special.2009.06.22

The sovereign representative acts, you might say, like a filter for the wills and passions of the people.

而君主代表的行动，就像人民意志和力量的过滤器。

耶鲁公开课 - 政治哲学导论课程节选

The original design of the ceramic filter came from a chemist in Guatemala,Fernando Mazariegos.

VOA: special.2009.06.22

The water filter costs little to make.

VOA: special.2009.06.22