As lead and arsenic pollution element are skew distribution, statistics of a natural background value and a content of lead and arsenic are worked out using median method of skew distribution.

由手铅、砷污染元素呈偏态分布，故采用偏态分布中的中位数法作了铅、砷自然背景值及含量的统计。

youdao

This is the most common element in the universe and so could come from many sources, but the fact that it tends to coincide with heavy-element pollution is telling.

氢是宇宙中最普遍的元素，可以有多种来源，但是它总是倾向于与重元素污染并存这一事实才是关键。

youdao

Pollution of hydraulic medium was a main cause that made hydraulic element wear earlier.

液压介质的污染是液压元件过早磨损的主要原因。

youdao

The FCX, on the other hand, runs on the world's most plentiful element--hydrogen--and doesn't produce any of the pollution that today's gasoline-powered cars do.

FORBES: Fueling Hope