The experimental result also shows that the nitrogen element on the surfaceofcontact black surface may be mainly in forms of amino group and nitro group.
此外，实验分析了接触法炭黑表面氮元素的组成，结果表明主要是以氨基和硝基的形式存在。
2
We wanted to know if the length of time food is in contact with a contaminated surface affected the rate of transfer of bacteria to the food.
我们想知道食物与被污染的表面接触的时间长短是否会影响细菌转移到食物上的速度。
3
An air burst is an explosion in which a weapon is detonated in air at an altitude below 30 km but at sufficient height that the fireball does not contact the surfaceof the earth.