The natural rubber has been gathered from the sap of plants for centuries.

天然橡胶是几个世纪以来从植物汁液中收集来的。

youdao

Natural rubber has been gathered from the sap of plants for centuries.

从植物汁液中收集天然橡胶已经有几个世纪的历史。

youdao

Natural rubber has problems, though.

然而，天然橡胶也有缺点。

youdao

Natural rubber has anchored the Liberian economy for more than 75 years.

VOA: standard.2009.09.13

The huge Firestone plantation east of the capital,Monrovia, remains the world's largest single natural rubber operation and was one of the first businesses to reopen after Liberia's long civil war.

VOA: standard.2009.09.13

He says synthetic rubber cannot be used, as there is a strong tradition of using natural rubber.

ECONOMIST: Sports anthropology

Because natural rubber is now scarce in Mexico, and the process of making a ball takes about 30 hours, the supply of balls is constraining the spread of the game.

ECONOMIST: Sports anthropology

The other amazing thing about this verdant and unique patch of India, rich in pepper, natural rubber, coconut, tea, coffee, cashews, and spices, is its bucolic backwater network of lagoons and canals.

FORBES: KERALA: Cruising The Waterways of India's Malabar Coast