THE LUNGS OF THE WORLD

Câu hỏi: Read the following passage and mark the letter A, B, C, or D to choose the word or phrase that best fits each of the numbered blanks from 25 to 29
THE LUNGS OF THE WORLD
It was once thought that forests and the wood that could be taken from them were in endless supply. Especially in areas like South America, where vast areas of the continent were covered by rainforests, logging and clearing of forests for farming seemed like a harmless endeavor. (25) _____________ the clearing of rainforests been kept in moderation, it may have become a stable source of wood and a(n) (26) _____________ for the people in the region. It was not, though, and the amount of damage that has been (27) _____________ to the entire planet has been terrible because of the clearing of rainforests. The rainforests are considered the lungs of the world because they breathe in carbon dioxide and breathe out oxygen. We need the oxygen to survive, and the more we clear rainforests, the more carbon dioxide begins to concentrate in the atmosphere. In addition to the clearing of forests, the burning of fossil fuels for energy (28) _____________ more carbon dioxide to the atmosphere. It makes the problems of global warming get worse, as we keep adding more carbon dioxide while simultaneously taking away the planet's (29) _____________ to deal with this gas.
The word or phrase which best fits the gap (26) is...
A. cost
B. livelihood
C. earning
D. job