The pit cover should be sealed over with tar paper or plastic.

顶盖必须用焦油纸或塑料封闭。

youdao

The paper analyzes the problem in separating oil tar by the mechanize trough. It raises the concrete transform plan, which gains the well economic efficiency in reality.

分析了机械化澄清槽分离焦油过程中存在的难题，提出了具体的改造方案，并且在实际中取得较好的经济效益。

youdao

This paper proposed to use coal tar and other processed products instead of partial heavy oil for float glass plants and analyzed related market supply, economic and technical feasibility.

主要提出了浮法玻璃工厂使用煤焦油及其深加工产品替代部分重油的可行性，分析了有关的市场情况、经济性和技术可行性。

youdao

In the next, he would reject traditional artists' tools in favor of found objects, black tar paper (textured and pebbly and quite iridescent, giving the impression of a midnight sky) or sentimental postcards, eliminating, in a sense, all traces of technique and skill--and even of the artist (some of the "objects" were assembled by carpenters).

FORBES: Miro's Creative Destruction